You're all guessing that she's a masochist trying to earn Jelly's ire, but the bomb is a bit much for that, no?
Though given what this series is tonally, that could still totally be the case, haha.
You're not wrong, but if her goal was to assassinate Jelly, her behavior in the previous chapter makes no sense.
She clearly knows what old Jelly was capable of. And her "
failed again" line after spilling soup for the second time implies that the torture may have been the whole point.
If this were old Jelly, she'd be handcuffed and chained in some dungeon awaiting torture. Even if her goal was to be alone with Jelly so she could assassinate her, she'd need inhuman strength to break the chains she'd likely be bound in. And if she were that strong, she could just attempt to kill Jelly without going through all this hassle.
My interpretation is that she tried using a bomb, knowing the guard will protect Jelly from it (which is why the bomb didn't explode right away). Everyone, especially the old Jelly, would immediately assume the new hire to be the culprit, and if spilling soup wasn't good enough, then surely a bomb would.
And now she's frustrated her plan
isn't working.