Apparel items would be giving these other players more coins when they win. There are some apparel items that have the bonus % to coins won in coin room rounds. Equipping these items and upgrading them will give you that bonus as well. For example, the Max Shoes would have this bonus.
You may be confusing XP with Coins. The Weekly Goals will give you 500 XP, which counts towards your level and advancing in level.
Best,
WGTShamwow