Players that don't know the technical term "billboarding" might use this as a way to say that the images of the food are "flat" unlike the rest of the 3D modeled environment. Just a suspicion!

I can also be used for derogatory connotations; Another example is for Smash Brothers specifically, the Byleth character's ultra move has a flat image of a character in their game and people call it "png sothis" (character name) to suggest that it's low-effort or not well made

Also that they use a more realistic style compared to much of the in-game art assets.