On Core 15.0 / x86_64, cheese.tcz depends upon gnome-desktop.tcz to provide libgnome-desktop-3.so.19 but gnome-desktop.tcz actually provides libgnome-desktop-3.so.20.
Symlinking /tmp/tcloop/gnome-desktop/usr/local/lib/libgnome-desktop-3.so.20 to libgnome-desktop-3.so.19 allows cheese to run, however I did not test beyond that as I don't actually have my web cam handy at the moment.