You can add pictures to the various spaces in your listing.
If you go to "edit listing, listing details", then scroll down to "property and rooms", and then go to "rooms and spaces", clicking on the little link to the left saying "edit", you'll get a list of all the rooms you've added to your listing. There you can add pictures to each space if you click on the little down arrow next to each room. You can also "Edit rooms and spaces" to add rooms and spaces.
If you change the picture associated with the bedroom, that is what will appear. Does that help?