there is a button at the bottom for this.
This is there to aid discovery. A user might not know they can use the info pane to edit a photo's metadata
Sorry to say but then the user might be really stupid. Obviously the right pane is there for adding/editing photo metadata. Photographers are so used to software like iPhoto, etc they know the purpose of the info pane. Keep the UI clean as possible.
Bug watches keep track of this bug in other bug trackers.
This is there to aid discovery. A user might not know they can use the info pane to edit a photo's metadata