diff --git a/plugins/openchoreo-react/src/components/YamlDiffViewer/YamlDiffViewer.tsx b/plugins/openchoreo-react/src/components/YamlDiffViewer/YamlDiffViewer.tsx
index 82d103ea9..e70aedca8 100644
--- a/plugins/openchoreo-react/src/components/YamlDiffViewer/YamlDiffViewer.tsx
+++ b/plugins/openchoreo-react/src/components/YamlDiffViewer/YamlDiffViewer.tsx
@@ -48,17 +48,22 @@ const useStyles = makeStyles<Theme, StyleProps>(theme => ({
     whiteSpace: 'nowrap',
   },
   container: ({ height, isDark }) => ({
-    height,
     fontSize: '0.75rem',
     border: `1px solid ${theme.palette.divider}`,
     borderRadius: theme.shape.borderRadius,
     overflow: 'hidden',
     backgroundColor: isDark ? '#1e1e1e' : '#fafafa',
-    '& .cm-mergeView, & .cm-mergeViewEditors': {
-      height: '100%',
+    // Per CodeMirror's MergeView docs: views are not scrollable by default —
+    // the .cm-mergeView itself must have a height and `overflow: auto` to
+    // become the scroller. Both panes are children of .cm-mergeView, so they
+    // scroll together as one unit. CM's baseTheme forces inner .cm-scroller
+    // to height:auto + overflow:visible when nested in a .cm-mergeView, so
+    // we don't override those.
+    '& .cm-mergeView': {
+      height,
+      overflow: 'auto',
     },
     '& .cm-editor': {
-      height: '100%',
       backgroundColor: 'transparent',
     },
     '& .cm-scroller': {
diff --git a/plugins/openchoreo/src/components/Environments/EnvironmentOverridesPage.tsx b/plugins/openchoreo/src/components/Environments/EnvironmentOverridesPage.tsx
index 0733e5a8f..f750fea6c 100644
--- a/plugins/openchoreo/src/components/Environments/EnvironmentOverridesPage.tsx
+++ b/plugins/openchoreo/src/components/Environments/EnvironmentOverridesPage.tsx
@@ -708,7 +708,7 @@ export const EnvironmentOverridesPage = ({
               disabled={saving || deleting}
               style={{ marginRight: 8 }}
             >
-              View diff
+              View release diff
             </Button>
           </span>
         </Tooltip>
diff --git a/plugins/openchoreo/src/components/Environments/components/ComponentReleaseDiffDialog.tsx b/plugins/openchoreo/src/components/Environments/components/ComponentReleaseDiffDialog.tsx
index f21122047..a648c34ac 100644
--- a/plugins/openchoreo/src/components/Environments/components/ComponentReleaseDiffDialog.tsx
+++ b/plugins/openchoreo/src/components/Environments/components/ComponentReleaseDiffDialog.tsx
@@ -74,25 +74,29 @@ export const ComponentReleaseDiffDialog = ({
     setOriginal(null);
     setModified(null);
 
+    // Diff orientation: LHS shows the target env's *current* release ("before"),
+    // RHS shows the upstream env's incoming release ("after"). The dialog title's
+    // `upstreamEnv → targetEnv` arrow still reflects promotion direction, not
+    // LHS → RHS.
     const fetches: Array<Promise<unknown>> = [];
-    if (upstreamReleaseName) {
+    if (releaseName) {
       fetches.push(
-        api.fetchComponentRelease(entity, upstreamReleaseName).then(res => {
+        api.fetchComponentRelease(entity, releaseName).then(res => {
           if (cancelled) return;
           if (!res?.success || !res.data) {
-            setError(`Couldn't fetch ${upstreamEnvName}'s release manifest.`);
+            setError(`Couldn't fetch ${environmentName}'s release manifest.`);
             return;
           }
           setOriginal(YAML.stringify(res.data));
         }),
       );
     }
-    if (releaseName) {
+    if (upstreamReleaseName) {
       fetches.push(
-        api.fetchComponentRelease(entity, releaseName).then(res => {
+        api.fetchComponentRelease(entity, upstreamReleaseName).then(res => {
           if (cancelled) return;
           if (!res?.success || !res.data) {
-            setError(`Couldn't fetch ${environmentName}'s release manifest.`);
+            setError(`Couldn't fetch ${upstreamEnvName}'s release manifest.`);
             return;
           }
           setModified(YAML.stringify(res.data));
@@ -146,28 +150,28 @@ export const ComponentReleaseDiffDialog = ({
           <YamlDiffViewer
             original={original}
             modified={modified}
-            originalLabel={`${upstreamEnvName} (${upstreamReleaseName})`}
-            modifiedLabel={`${environmentName} (${releaseName})`}
+            originalLabel={`${environmentName} (${releaseName})`}
+            modifiedLabel={`${upstreamEnvName} (${upstreamReleaseName})`}
             height="60vh"
           />
         )}
-        {previewMode === 'source-only' && original && (
+        {previewMode === 'source-only' && modified && (
           <>
             <Typography variant="body2" color="textSecondary" gutterBottom>
               <strong>{environmentName}</strong> has no release yet — this is
               the manifest that will be created from{' '}
               <strong>{upstreamEnvName}</strong>.
             </Typography>
-            <YamlViewer value={original} maxHeight="60vh" showLineNumbers />
+            <YamlViewer value={modified} maxHeight="60vh" showLineNumbers />
           </>
         )}
-        {previewMode === 'target-only' && modified && (
+        {previewMode === 'target-only' && original && (
           <>
             <Typography variant="body2" color="textSecondary" gutterBottom>
               <strong>{upstreamEnvName}</strong> has no release to compare;
               showing <strong>{environmentName}</strong>'s current manifest.
             </Typography>
-            <YamlViewer value={modified} maxHeight="60vh" showLineNumbers />
+            <YamlViewer value={original} maxHeight="60vh" showLineNumbers />
           </>
         )}
       </DialogContent>