A television viewer (usually male) who pauses, zooms in and/or slow-motion advances frames of provocative images, in a feeble attempt to see something "naughty".
My friend, who has as much access to porn and nudity as any other red-blooded American male, paused his TiVo to check out Katie Holmes's cleavage as she sat down for a talk show interview. It might be understandable if we had never seen her nude, but we have. So it's basically a waste of time which serves only to indulge his whim of seeing her less nude in a different position. Therefore, he is a Tivert.