Have you noticed an 8cm CD case is exactly the same size as a 3.5" floppy disk?

Have you noticed the slimline case is just too thick to fit in a 3.5" floppy drive?

And have you noticed that if it's opened, the case will fit in a floppy drive?

Sooner or later a child or other computer user near you is likely to notice...

And discover it won't come out again...

If it's one of the currently popular deeply recessed drives, an easy way to remove it without harming anything is to put a slight curl in the end of a business card, slide it into the drive & lift the door flap free from where it conveniently snags on the end of the case.