diff --git a/src/vs/sessions/contrib/changes/browser/changesView.ts b/src/vs/sessions/contrib/changes/browser/changesView.ts
index b1affdd3cba..53803af7c84 100644
--- a/src/vs/sessions/contrib/changes/browser/changesView.ts
+++ b/src/vs/sessions/contrib/changes/browser/changesView.ts
@@ -319,7 +319,8 @@ class ChangesViewModel extends Disposable {
 
 		// Active session isolation mode
 		this.activeSessionIsolationModeObs = derived(reader => {
-			return activeSessionRepositoryObs.read(reader)?.workingDirectory === undefined
+			const activeSessionRepository = activeSessionRepositoryObs.read(reader);
+			return activeSessionRepository?.workingDirectory === undefined
 				? IsolationMode.Workspace
 				: IsolationMode.Worktree;
 		});
@@ -331,7 +332,8 @@ class ChangesViewModel extends Disposable {
 				return constObservable(undefined);
 			}
 
-			const workingDirectory = activeSessionRepositoryObs.read(reader)?.workingDirectory;
+			const activeSessionRepository = activeSessionRepositoryObs.read(reader);
+			const workingDirectory = activeSessionRepository?.workingDirectory ?? activeSessionRepository?.uri;
 			if (!workingDirectory) {
 				return constObservable(undefined);
 			}
@@ -713,46 +715,49 @@ export class ChangesViewPane extends ViewPane {
 			});
 		});
 
-		const headCommitObs = derived(reader => {
+		const allChangesObs = derived(reader => {
 			const repository = this.viewModel.activeSessionRepositoryObs.read(reader);
-			return repository?.state.read(reader)?.HEAD?.commit;
+			const firstCheckpointRef = this.viewModel.activeSessionFirstCheckpointRefObs.read(reader);
+			const lastCheckpointRef = this.viewModel.activeSessionLastCheckpointRefObs.read(reader);
+
+			if (!repository || !firstCheckpointRef || !lastCheckpointRef) {
+				return constObservable(undefined);
+			}
+
+			const diffPromise = repository.diffBetweenWithStats(firstCheckpointRef, lastCheckpointRef);
+			return new ObservablePromise(diffPromise).resolvedValue;
 		});
 
 		const lastTurnChangesObs = derived(reader => {
 			const repository = this.viewModel.activeSessionRepositoryObs.read(reader);
-			const headCommit = headCommitObs.read(reader);
+			const lastCheckpointRef = this.viewModel.activeSessionLastCheckpointRefObs.read(reader);
 
-			if (!repository || !headCommit) {
+			if (!repository || !lastCheckpointRef) {
 				return constObservable(undefined);
 			}
 
-			const lastCheckpointRef = this.viewModel.activeSessionLastCheckpointRefObs.read(reader);
-
-			const diffPromise = lastCheckpointRef
-				? repository.diffBetweenWithStats(`${lastCheckpointRef}^`, lastCheckpointRef)
-				: repository.diffBetweenWithStats(`${headCommit}^`, headCommit);
-
+			const diffPromise = repository.diffBetweenWithStats(`${lastCheckpointRef}^`, lastCheckpointRef);
 			return new ObservablePromise(diffPromise).resolvedValue;
 		});
 
-		const isLoadingLastTurnObs = derived(reader => {
+		const isLoadingChangesObs = derived(reader => {
 			const versionMode = this.viewModel.versionModeObs.read(reader);
-			if (versionMode !== ChangesVersionMode.LastTurn) {
+			if (versionMode !== ChangesVersionMode.AllChanges && versionMode !== ChangesVersionMode.LastTurn) {
 				return false;
 			}
 
-			const headCommit = headCommitObs.read(reader);
 			const repository = this.viewModel.activeSessionRepositoryObs.read(reader);
-			if (!repository || !headCommit) {
+			if (!repository) {
 				return false;
 			}
 
-			const result = lastTurnChangesObs.read(reader).read(reader);
-			return result === undefined;
+			const allChangesResult = allChangesObs.read(reader).read(reader);
+			const lastTurnChangesResult = lastTurnChangesObs.read(reader).read(reader);
+			return allChangesResult === undefined || lastTurnChangesResult === undefined;
 		});
 
 		this.renderDisposables.add(autorun(reader => {
-			const isLoading = isLoadingLastTurnObs.read(reader);
+			const isLoading = isLoadingChangesObs.read(reader);
 			if (isLoading) {
 				this.changesProgressBar.infinite().show(200);
 			} else {
@@ -762,28 +767,21 @@ export class ChangesViewPane extends ViewPane {
 
 		// Combine both entry sources for display
 		const combinedEntriesObs = derived(reader => {
-			const headCommit = headCommitObs.read(reader);
-			const sessionFiles = sessionFilesObs.read(reader);
 			const versionMode = this.viewModel.versionModeObs.read(reader);
 
-			let sourceEntries: IChangesFileItem[];
-			if (versionMode === ChangesVersionMode.LastTurn) {
-				const lastTurnDiffChanges = lastTurnChangesObs.read(reader).read(reader);
+			const sourceEntries: IChangesFileItem[] = [];
+			if (versionMode === ChangesVersionMode.BranchChanges) {
+				const sessionFiles = sessionFilesObs.read(reader);
+				sourceEntries.push(...sessionFiles);
+			} else if (versionMode === ChangesVersionMode.AllChanges) {
+				const allChanges = allChangesObs.read(reader).read(reader) ?? [];
+				const firstCheckpointRef = this.viewModel.activeSessionFirstCheckpointRefObs.read(reader);
 				const lastCheckpointRef = this.viewModel.activeSessionLastCheckpointRefObs.read(reader);
-
-				const diffChanges = lastTurnDiffChanges ?? [];
-
-				const modifiedRef = lastCheckpointRef
-					? lastCheckpointRef
-					: headCommit;
-
-				const originalRef = lastCheckpointRef
-					? `${lastCheckpointRef}^`
-					: headCommit ? `${headCommit}^` : undefined;
-
-				sourceEntries = toChangesFileItem(diffChanges, modifiedRef, originalRef);
-			} else {
-				sourceEntries = [...sessionFiles];
+				sourceEntries.push(...toChangesFileItem(allChanges, lastCheckpointRef, firstCheckpointRef));
+			} else if (versionMode === ChangesVersionMode.LastTurn) {
+				const diffChanges = lastTurnChangesObs.read(reader).read(reader) ?? [];
+				const lastCheckpointRef = this.viewModel.activeSessionLastCheckpointRefObs.read(undefined);
+				sourceEntries.push(...toChangesFileItem(diffChanges, lastCheckpointRef, lastCheckpointRef ? `${lastCheckpointRef}^` : undefined));
 			}
 
 			const resources = new Set();
@@ -817,7 +815,7 @@ export class ChangesViewPane extends ViewPane {
 
 			let lastHasChanges = false;
 			this.renderDisposables.add(bindContextKey(ChatContextKeys.hasAgentSessionChanges, this.scopedContextKeyService, reader => {
-				if (isLoadingLastTurnObs.read(reader)) {
+				if (isLoadingChangesObs.read(reader)) {
 					return lastHasChanges;
 				}
 				const { files } = topLevelStats.read(reader);
@@ -956,7 +954,7 @@ export class ChangesViewPane extends ViewPane {
 
 		// Update visibility and file count badge based on entries
 		this.renderDisposables.add(autorun(reader => {
-			if (isLoadingLastTurnObs.read(reader)) {
+			if (isLoadingChangesObs.read(reader)) {
 				return;
 			}
 
@@ -982,7 +980,7 @@ export class ChangesViewPane extends ViewPane {
 			this.summaryContainer.appendChild(linesRemovedSpan);
 
 			this.renderDisposables.add(autorun(reader => {
-				if (isLoadingLastTurnObs.read(reader)) {
+				if (isLoadingChangesObs.read(reader)) {
 					return;
 				}
 
@@ -1140,7 +1138,7 @@ export class ChangesViewPane extends ViewPane {
 		this.renderDisposables.add(autorun(reader => {
 			const entries = combinedEntriesObs.read(reader);
 			const viewMode = this.viewModel.viewModeObs.read(reader);
-			const isLoading = isLoadingLastTurnObs.read(reader);
+			const isLoading = isLoadingChangesObs.read(reader);
 
 			if (!this.tree || isLoading) {
 				return;