The idea is to build this as a light box behind a standard windowpane frame. Like this one.[1] With a 120mm short focal length, the unit only needs to be about 150 - 200mm deep, if you angled the optics so you get light at a 30 degree angle or so. (Horizontal sun rays would look wrong.) That's a convenient size; you could hang it on a wall, like a rather bulky picture.
The satellite dish is more dramatic so I don't blame him for leading with it :)