Why is everyone taking that weird stance with their arms making an X and their fingers crossed? I get that it's supposed to be a blocking stance, but the reference or joke escapes me. And why the "gentleman" faces?
It's a One Piece reference. There's a character that ate the barrier-barrier devil fruit, which gives him the power to make barriers. He does that pose whenever he makes a barrier.
Actualy that barier pose is something that already there in Japan since long ago. Children use it as a barrier when other children touch something dirty or gross and they want to touch other children and infect them they cross finger to make barrier so they don't get infected.