I dunno wtf anymore, and this is like confusing like shit Wtf, not like this is awesome wtf like in rosen garten
So something we have learnt within the series is that ghosts, and other supernatural elements are influenced by thematics and tropes. Basically, if it's a trope that something would happen then it actually becomes more likely to happen, like if someone said "When we get out of here Im going to confess to her!" they would actually become easier for a ghost to kill.
Not all tropes apply equally in all contexts, and ghosts, who want to kill people, lean into and rely on horror tropes for that, because in horror the monster usually kills the human. Hence the whole thing from earlier about taking horror and changing the genre to action, making it so that different tropes apply and can be leveraged by both ghosts and exorcists.
The difficulty with that is in order to take advantage of it you need to change the whole vibe of the situation you cant just say "The genre is action now." You actually need to make the situation look and feel like something straight out of an action movie, which you can do by saying stuff like how "Youre already dead," or by really confidently kicking the ghost. The kicking thing is a gamble though because if the kick lands and deals damage then the genre changes to action, if it doesnt then the attack actually reinforces the genre as horror. That's why when the kick in chapter 41 failed Kagura stopped attacking and went on the defensive (while still trying to make it feel like action) while everyone else ran away, and when the ghost tried to force an end to the scene she ran away as well. After finding Shinonome she created an action atmosphere with her and brought that atmosphere back to the ghost, hoping to change the genre that way, though she probably did ALSO just want to fight Shinonome.
The ghost saw what was happening and threw in the beachball. Maybe this was to weaken the action atmosphere with comedy and make it easier to switch the genre back to horror afterwards.
For Shinonome specifically, something that has worked really well as a vibe reset and genre change away from horror is when she does something crazy that confuses the ghost, which would take this scene away from action comedy to full comedy which would be harder to subvert to horror than even pure action was! Clearly, that bit at the end is an attempt to emulate that!
At least that's my reading of it, the whole series works pretty well if you interpret it that way, it is pretty consistent with its internal logic
