Set default MiniMax location reference

optimized/image-to-video/minimax-h3-r2v-master/prompt-guide.md

@@ -9,6 +9,9 @@ matching the local ComfyUI workflow that Chris is actually using.
 Bundled default Subject 1 character reference image:
 `references/default-character-reference.jpg`
 
+Default location reference for `<Picture 1>`:
+`https://www.juliettesinteriors.co.uk/wp-content/uploads/2020/03/luxury-designer-italian-button-upholstered-sofa-4.jpg`
+
 ## Official MiniMax doc takeaways
 
 Based on:
@@ -39,6 +42,8 @@ Key points worth preserving:
 
 - Treat `<Picture 1>` as the environment / master-scene reference when an
   environment reference is used.
+- Use the Juliette's Interiors sofa image above as the default `<Picture 1>`
+  location reference until a shot-specific environment image replaces it.
 - Treat `references/default-character-reference.jpg` as the default file to
   load into `<Picture 2>` when you need a starter Subject 1 full-body
   reference and have not chosen a different one yet.