Stadium cup holder "nubs"

I was at a baseball game the other day, and noticed something that has had me puzzled for years. On the cup holder, there are two plastic nubs or posts sticking out of the top (you can see an example here: What is the purpose of these nubs? I have a couple of potential ideas, but I don’t want to taint anyone else’s thinking yet.

It’s so that people won’t sit on them with their large heavy baseball physiques and break them off?

If that were the case, they would probably be on the other side of the cup holder. These tend to be close to the seats in front of them, where you probably wouldn’t even be able to sit on them if you tried.

Just a guess, but it’s common for stadiums to use the cup holders as a location for advertising and branding. I’d guess that’s to hold a cardboard or plastic advertising card/insert/sleeve/what have you.

WAG - Some movie theaters have snack trays that hold a soda, popcorn bag and snack box. These snack trays attach to the cupholder on the theater seats.

It could be something like that, with the pins as some support pins?

Hooks for handbags?

It’s for give-away bags. I was at the All-Star Game last year, and there were plastic bags of promotional materials and a color t-shirt (for a stadium-sized American flag). They were hung off of those pegs.