Zoe has a little blue/purple-ish bag for her spells

I'm doing a cosplay & noticed something on Zoe's splashart next to her other trinkets. It looked like one of those old open-up phones to me & I looked at her ingame very close too. I still couldn't figure out what it is so I looked at her model on LoLKing. It turned out it was a little, blu/purple-ish bag.

Now my question is: Could she put her spells in it? Because if yes, I'm going to buy plastic balls and put pictures of spells in it to put it in the bag later xD Probably going to do this one way or another but still: 1) wanted to share that & 2) wanted to hear others opinions.

PS: If you're already reading this, (I know it's "a bit" early, but...) is Riot going to be at Gamescom 2018 (I live in South Germany)? Because they weren't 2017 and I really would like to go there with my first cosplay (if not counting my way to easy & fast made Frisk costume with old suff from my closet that I wore once xD). I know they haven't said anything yet but maybe someone heard something somewhere, idk.