System: Fedora 21 x86_64 8 GB Nvidia GFX drivers
if a video call is done, the "show yourself" functionality does not
work. you just get a blank(most of the time black) screen behind the
picture of the contact you speak to.
If multiply user in a video conference, the own picture is only show if
all members activate video.
All other clients where Jitsi too ( mixed Linux and Windows ).