That IS the question, and apparently the answer is 'mystery mirror magic', which is satisfyingly alliterative but unsatisfying in any other particular. Words like these lurk behind Papyrus' teeth, though he doesn't begin to offer them. Her straightforward comment is pretty straightforward, with no room to argue directly.

"Well... I guess that's true." He hums uncertainly for a moment, then adds, "but that doesn't mean you're not welcome! Mirrors might be cold, sideways welcome mats, but something invited you here."

Truth be told, they haven't even entered the tall grass of the metaphor weeds Papyrus has to offer. Toby may someday find herself discouraged or even frustrated in conversation with him.