So, Angus being there for this raises that issue of how the ruins even got here and got ruined while Angus was still a kid again, but that's probably less urgent then the way Angus is reacting to remembering. Sans isn't great at this, but he puts a hand on Angus's shoulder to try and steady him.

"D'you remember the details? What was she doing you wanted to stop? Is this picture some kinda metaphor or was this actually happening?"