I think a town NPC will need like minimum 3 solid blocks (right next to each other) in a room to stand on the night, at rain etc.
since most of the floor is platform, that doesn't counts for them like that. there's only 1 solid block on the right, so that is not valid for this purpose either.
there is only 2 on the other side if the gate is closed, but I guess when it's open, it counts either the block the gate is on - thus there are 3 solid blocks - or maybe even the rest of blocks in the other room (this is unlikely though)
the platforms at the window doesn't matter, they are counted as walls for housing purposes.