Are the walls in your garage white? To keep light from reflecting around the room, paint all the walls and the ceiling a dark none reflective color like, oh I donno, black. That will keep the excess light you don�t want from reflecting back in to the room.
In pictures the units are usually being used in a larger room so they cant totally wash the whole room. And in demo room at stores, they usually have the walls and stuff painted a dark color.