The number of photos in a Foto-Flat is not fixed. It depends on how many photos we have taken of you and whether we have been able to assign them correctly. Basically, all photos in which you can be seen are part of the Foto-Flat. If we could not assign some photos, you can add them to the Foto-Flat afterwards for free. You can find out how to do this under How do I find and mark more photos of myself?