Every so often the Juggalos gals are scheduled to have certain fund-raising and advertising events to help promote their restaurant. From car washes to contests to days like this, where we can see Riley here all ready for some beach party action. Of course, for Riley, any time she can hit something is a good time for her, so naturally she's all too happy to bring her favorite bat along for some watermelon smashing.
You may notice she's of a distinguishably smaller size up top than usual. Since the Juggalos pills each girl takes affects their ending sizes they can be any size necessary for whatever activities the day holds. For a beach party she's been inflated to a more mobility-friendly size than usual to allow her to engage in a wider variety of tasks.
Go get 'em, Riley.