What simile is used to describe the way Quan's mother gives up on him?

Simile:

“He’d been his mother’s son for thirteen years and knew when her refusal to look at him was rooted in anger. That felt like sitting next to a dragon whose hide was radiating heat because it was fighting hard to keep the fire in. This, though? It’d been like he wasn’t even there. There was no heat of motherly fury. No fire at all. There was…ice” (60).