A little too personal
Your friendly neighborhood Spiderman is used to being adored and congratulated. Saving the world from aliens and hanging out with Thor and Captain America are on his daily to-do list. He obviously knows that there’s plenty of Spiderman merchandise out there and he’s probably fine with that.
I’m not sure he’d be too keen on this particular piece of merchandise, though, or the design idea behind it. Given that you usually want a tissue because you need something clean, pulling it out of someone’s behind isn’t the best choice. Also, it looks pretty weird on the shelf.