Watch the episode called "Drone". That's the episode where Seven's nano-probes accidently mix with the Doctor's mobile emitter and with the DNA of a crewman create a 29th century Borg. Before they know what's happening with the emitter, B'Elanna has an overnight analysis done on it. At 0600 hours (6 am) the Doctor impatiently awakens B'Elanna for the results. She gets up, walks into the bathroom, takes off her clothes and is about to go into the sonic shower when the Doctor appears on a flat screen on a flat wall. She quickly covers herself with a towel and then throws it onto the screen to cover it. The towel stays! How can it stay up if the wall and screen are flat?