Late edit: I saw it a few days and didn’t rewatch before posting. So I forgot that she actually gets his hopes up when she opens the door and grabs a box of Hot Pockets or something off the door. So I guess it wasn’t JUST for the snowman which makes it a little weirder since he’s taking up 80% of a freezer that she’s actively using 
Also, bizarrely, the snowman seems to be shivering when she opens it.