Karl Max said:Thor is holding the hammer Mjølner, which is the hammer Thor the thunder god use to creat thunder. According to nordic mythology when Thor the thunder god swings the hammer the thunder comes. His team mates is praising Thor the god of thunder. Quite funny I think when you understand the references.
Even without the references it's still funny in a "what the hell is this trainwreck and who the hell greenlighted it?" kind of way.