just... what?

there's an anger vein on Momiji's hand, and Aya's arm is trembling...and there's a wolf wearing shorts in the middle panel. and yet....I've not the slightest clue as to what is going on...

I think the vein in Momiji's hand and Aya's trembling arm implies that they are trying to pull the blanket into their side because it's too small for both of them.
This comic's context, however, we need someone to translate this first.

I think that Aya is saying that dogs need less covering and Momiji is resisting that notion.