[The initial startled yelp is lost offline, where only Papyrus, his Phylax, and anybody else in the area might hear him. By the time he figures out and switches over to the video upload, he's only wide-eyed and a little shrill with surprise.]

Oh my god! Mettaton!! I'm caught off guard... because I didn't expect to see you!

[Like that. With ears. Now he can believe it's been almost two months, that one startling guy cautioned that Mettaton was here and as a double monster, but had he mentioned the ears...? The moon thing almost isn't as surprising now.]

I heard you were here, before, but. I haven't seen, uh, hide nor hair of you...?

[Hide nor hare, even.]