Alternate view of the Anderson abode…
Note the odd angle of the walls, etc.
Then refer to Mae’s Awesome Analysis of Blaine’s Room.
The slanted feature you’ve mentioned strongly indicates that Blaine’s room is at the top of his house, as those features (like sloped ceilings) are integral parts of the building’s structure. I am by no means a building expert (lol, no) but going on my own knowledge, houses with 2 or more floors tend to taper at the top and a room like Blaine’s would normally either be a storage room, or at best modified into a spare/guest room. (more on the potential original uses for this room to come near the end of this post)
Look at Blaine’s door as well - it has slats in one half like a utility room door. The one window I can see is off-center, very small, and the backlit screen they’ve used shows the tops of tree branches. The wall facing the dresser with the mirror and stereo is an internal one and won’t have another window, so that’s the only one he has. I really don’t think this room was intended for daily use.
And here is where I get to freak out about one very minute headcanon I’ve always had about Blaine: that he picked the bedroom tucked furthest away from everything. It has a nested quality about it, almost like a tree house - an escape. I have never once imagined Blaine’s bedroom any other way. Nothing grand, nothing bright or cheerful, and nothing at all like most teenage bedrooms look. Remote, dark and private.
See slanted wall. (Photo courtesy of rhilex)
(Gif courtesy of blaineandersons)
Note the single window. Light obviously coming from a streetlight outside with a gobo effect from any possible nearby trees…
So until proven wrong, that room above the driveway is Blaine’s room in my mind.