These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
YMMV: The Sisters Grimm
Jerkass Woobie: Being trapped in a mirror for hundreds of years and having to deal with cruel owners made Mirror bitter and led him to become the Master.
For the readers, we have the illustration of Little Red Riding Hood at the end of the second book. Sure, the description of the sweet Little Red Riding Hood with the smile of a serial killer is disturbing in its own right, but the picture... it fills in the little gaps in the imagination that were best left blank.
Also, the thought of the more unpleasant fairy tale characters being both alive and at large, and the idea that the terrible things some of them did actually happened... It becomes Fridge Horror of finest caliber.
At one point, the flesh literally melts off the bones of one character.