I guess "stock" in the name suggests that Mack simply took the inspirational picture and overpainted it.

I love the overall setting on this one, the shadow of the fairy that suggest this is somehow on a plane, and the curiosity and dynamic of the fairy itself. Also how the inspiration pic was improved a lot, not quite visible on the first glance but the lower bottom part of the hair is quite different, so is the face itself around the eyes, and the nose and mouth is a ton better than on the inspiration.
Also like the colour selection

It feels very soothing to me, love to look at it over and over again.

FWIW Found it the first time in the freax art album, and fell in love with it ever since.