Hedonic eating is eating for the reward of it — because food looks, smells, or tastes good, because it's there, or because you're stressed, bored, or celebrating — rather than because your body needs energy. It sits alongside homeostatic hunger, the physical drive to eat that rises as energy runs low. Highly palatable foods, food advertising, and habit all pull on the hedonic side, and for many people it accounts for a large share of what they eat beyond need.
It matters on a GLP-1 because these medications act on reward circuits in the brain as well as on the gut, which is why many people describe cravings and constant thoughts about food ("food noise") going quiet — often more striking than the reduction in physical hunger. That effect can fade at lower doses or after stopping, so noticing the difference between hedonic and physical hunger is a useful skill to build during treatment. See what suppression, satiation, and satiety mean on a GLP-1.