This is just a totally brain dead take. Maybe the SNAP recipient likes brown mustard and prioritizes it. And you don’t care that much so you don’t prioritize it. If it mattered to you, you would budget to get fancy mustard.
If you really do feel you can’t afford fancy mustard, you shouldn’t be mad at the person who earns food assistance and then uses it to buy fancy mustard, you should be mad that you aren’t making enough to afford fancy mustard.