You may have intended it as a joke, but the first thought that occurred to me was also that it was some kind of armor, specifically some kind of scale mail, disguised as leaves. Perhaps the trees are ents wearing leaf-like scale mail armor?
The tentacle-like branches coiling from the wall behind the rightmost cell in panel 1 scare me. It has *got* to be some kind of monstrous tentacled entity disguised as a tree.
It is a trap! Of course.
That's at least a +10 bonus in Knowledge(Gardening)
it's a wooden octopus in this spring's fashionable elven scale-mail armor!
will they live through the square leaves to ever find out, though?