Define what the room must do
List the activities, storage needs, fixed elements, and furniture that must remain. This gives each generated direction a practical test beyond appearance.
Use variants to narrow the brief
Compare a few layouts and moods while keeping the same photo. Save the parts that work, then use those references when measuring furniture or talking with a designer.
Do not treat the preview as a floor plan
Generated concepts are not dimensionally reliable. Measure doors, windows, walkways, outlets, and furniture before making changes.