CURRENT (thanks DeadLantern)
OUTDATED below, after the new Xeno weeds sprites.
► Show Spoiler
Old trap sprite on new weed sprite.
Covers on traps are sometimes just crazily good, e.g. helmet + gas mask, blowtorch + wood, or simply a M41A.
I left out the ones under alien corpses, because no way you can see it anyway.
I noticed when I place trap on the tile with alien blood, it removes the alien blood (or puts it under the trap), so dev did take some steps on it. I wonder what covers are ok?