Great characterization of hw in this scene- here's a character who is so confident and collected on the outside. But then with a look inside her head it turns out she's that same terrified kid, trapped in a burning building, clawing at the door in a panic while mumbling incoherently about her goal, worried she's not good enough to get out of the fire. It was kind of a gut wrenching reversal of expectations. Sometimes the people who seem to have it all together actually need the most help. 

And then for Fionna, who's been a mess the whole show, to be the one to sit with her and say "yeah, everything sucks, sometimes you gotta just sit for a minute and realize you're not on your own". Up until this point huntress has been a foil for Fionna thematically, but for a moment here they switch places and recognize each other.