That makes sense... Probably. Happening at the same time... Being the same thing... [The arms and soul orb seem to fit together, anyway.

They don't explain the shifting feathers on Sans's head, even if there's the slightest similarity between the winged orb and a winged skull. Papyrus scratches at the side of his own skull, to wipe off a little sweat and try to shake the sympathetic sense of itching there.]

I can't believe, there was just no warning? [He doesn't mean to accuse Sans of lying, or forgetting something, though there's something skeptical slipping into the concern of his voice. Mostly he doesn't want to think something this drastic will happen so suddenly to him (again). Being an onlooker to another mysterious metamorphosis, without any changes of his own to be preoccupied, it's a different kind of horror. But there's plenty of horror and dissonance on his end. If it weren't for how rarely he dreams, and the sorts of things he dreams about, he'd be sure this wasn't real.]