No Spoilers
Emilia herself explains her contract with Puck is filled up with so many conditions, but most of them are trivial or... well. It also seems Puck freely adds up more conditions as time passes.
Those are not all but few of them.
I will be active only from 9 am to 5 pm
Do not ask my relationship with Beatrice
Do not look into mirror or go near large water
I will choose your hairstyle every morning
Groom my fur regularly
Have some exercise when you wake up and before going to bed.
Do not be picky about food
Talk with lesser spirits every morning and evening
ETC
You could see what most of the conditions are about.
