What does she mean by saying "face melted?" Is it a metaphor?

Rebecca

Here the phrase could have a couple of meanings. The first is that the food is spicy, so the heat from the food would figuratively "melt one's face". The second meaning is the slang term for "face-melting", which means something awesome or amazing! So she could be saying that the food will be amazing. However, I would say it means the first one, that the food is spicy. Ex: I feel like my face is melting from this heat and humidity. Ex: We're eating hot wings for dinner. Get ready to have your face melted. Ex: That was a face-melting concert! It was SO good!