A year and a half ago yours truly made it into this off-limits room off the Sistine Chapel and took some pics. Photos of this room do not exist. There are some old black and white photos in orbit taken just before conclave '58 and '63 (when the walls were covered in rich crimson damask).
In the Sistine Chapel after the newly elected pope weeps and accepts his election he states his new name and then enters this small room off the chapel to rest alone on this couch seen here. He then changes into one of three papal soutanes: a small, medium or large.
The bottom photo reveals the never before seen papal toilette. The bottom drawer/sliding box pulls out to reveal a fine translucent ware basin of porcelain. It has likely not been used in decades, but is a nice piece of history and is still kept in this spot today.