Except for the beanie and the grey clothing, I wouldn't have guessed that it's a thief. So if that's your angle, then I would do something much more obvious in terms of thievery. The gear change of emotions could also be more contrasty. For example, he's totally concentrated on stealing that TV, then the owner comes down in his pyjamas and sees him, the guy then switches gears and totally "acts" like he's the TV installation guy, and then as he sneaks out he's back in thief mode. Does that make sense? If you can understand all those beats and what's going on, without a thief clothing, then you succeeded. Having the guy look like a thief helps a lot, but try to act things out so that the persons behavior also informs the viewer that he is a thief. If it's at night, he'd careful to be quiet, so the movements would delicate. A regular TV installation guy wouldn't move like that, so that's already informing the viewer as to who that character is.
Also, think about tools he might use, that could add some funny things to the situation. Screw drivers, cables, little lamps, etc.
Hope that helps!