"Yeah... Don't think Ratchet would be too happy with that, no."

Roller sitting down means he's likely right at Bee's height. It's all right. He's used to it. Honestly this is all some mistake or accident or what have you. Otherwise this guy seems all right. Bumblebee is going to take the offered hand and give it a shake as best as he is able.

"Bumblebee."

Quite ironic, considering Bee had worked for Sentinel, hmm?