Since a few people asked... the book case is secure. Very heavy and screwed to the wall. No worries. :D
She has quite the sniffer considering her stubby nose. We've kept the treats there for over a year and she'd never done that before... then we realized we left a little peanut butter trainer treat out of the bag (they're tiny since they're for our foster puppy). We were super impressed she could smell that tiny thing up there since even the puppy with a "normal" nose couldn't smell it.