You pull out the items from the case, first you place the ring on your ring finger as it appears to be an engagement ring, it glows and your hair becomes much more fluffy big and soft and styles itself into a big ponytail with drills as your bangs (pic somewhat related only mint green) and you get a feeling that you might be in love with someone but not the bunny she seems more like a servant and it's more likely you have a lover back home and the ring let's you detect magic was the cause.
next, you try out the feathery hand fan which causes green sparkly mist to spread throughout the whole train as you fan it, seems like it can be used to amplify your mint powers and spread it without touch which reveals foot prints leading to the engine room, the reason the compact didn't reveal those because they weren't of magical origin, the mist even changes the bunny's leotard to a nice shiny emerald green color and added a subtle glittery make up to your face and a sparkle to your eyes and makes the corset not an issue despite how tight it is, the mist makes it feel like a snug hug and kinda comfy plus it smells nice, how minty!
finally, with the small key you follow the footsteps to the engine room and try pressing a button on the console only for it not to work so you place the key, the teeth of the key change shape, guess it's a magic skeleton key (eep! skeleton!) turning the key lights up the various buttons, you have a hunch one of these will fix this mess.
what button?>green button, it's your favorite colour>pink button, it's cute>purple button, the colour of magic>orange button, it's the brightest
joke option:>self destruct button, yeet the train! (don't actually pick this one)