Lucky Lucy looked fat and happy in her video--it cracked me up when you came up from behind with the camera and she lifted her head and froze like that for a few seconds...and you know they're smelling/sensing you, and then that slow, deliberate turn of the head to confirm your identity with sight...
Taco exhibited that exact same process this morning when I tried to sneak up behind her to see how much of her food she was eating. She always detects me and always gives me that look over her shoulder, "Are you still there? You know I won't eat any more till you're gone!"