>>57894905
It's honestly kinda worse than that.
The mega in the anime has it's gem shrink as it takes damage. So of course, they immediately recognize the mega design clashes horribly with any reasonable way this creature should move, so they speed up the process by just having it shrink immediately, so they can have it fight in it's "base" form again, just with red eyes.
They're basically trying to have their cake and eat it to.
>"Whoa! Look, he's mega evolving!"
>"Oh... this design can't functionally move at all."
>"W-well, look, it's defenses are down, so it's can move again! Wasn't that such a cool mega evolution?"