I could be wrong but, with the otsukare sanda translation, I'm pretty sure its supposed to be a bread pun. I don't think she is saying thunder 「サンダー」 I think she is making a pun by combing sandwich 「サンド」with the 「さま」part of 「おつかれさま」think the ド at the end becomes a ダー to imitate how its common...