2x4 Fluorescent Troffers Mounted In-Between Drop-Ceiling Tiles?

Here are some common 2-lamp F32T8 2x4ft fluorescent troffer light fixtures in a hallway at my school. Notice anything odd about them? It took me a month to notice this, but these fixtures are halfway mounted between two drop-ceiling tiles, with 1x4 tiles on either side! I don't recall ever seeing an installation like this until now, very odd! It sure does look neat though. Lamps are most likely GE F32T8/SP41/ECO, ballasts are most likely electronic instant-start.