Stereoscopic UIs provide new opportunities but also challenges for UI design. In investigating interaction with a S3D mobile UI, Huhtala et al. studied a find-and-select task on a mobile touch screen [1]. They reported that both performance (task completion The use case in our prototype is the sharing of multimedia content, photos, between two S3D mobile phones. Sharing photos is a relevant use case for mobile phones, and it has already been quite extensively investigated in mobile HCI research, e.g. by Kindberg et al. [2] already in 2005. We extend mobile photo sharing to include a special display technique, autostereoscopy. In doing so, our aim is not only to demonstrate yet another way to share photos, but to seek a meaningful way to design S3D UIs with a relevant use case.