She's acting as a point of reference, showing that the scene would be confusing to anyone that just happened to stumble upon it and thus illustrating the humor for the audience.
Plus Yukari's 0_0 + :3 is always funny to look at... :)
Ah!Point CardHold up, Momo-chanReward♥If you're going to the supermarket...Here! We should save the points on this cardI'm going out to buy a few thingsStampKado taniI don't really know which one is where...Oh I know! We should use this one too!Koy amaAnd there we go!The Momo-chan Errand Card!