The skin itself is well made. I like the textures on the clothing and the dragon as well.
Something to think about and possible improve on would be the particles for Pixs attacks.
The passive bolts would be a lot more fitting to the skin if they were small balls of fire streaking at the enemy instead of the usual purple little shock bolts and perhaps a little sound change on them wouldn't hurt either.
Another thing to look at is the effects of her shield. Cast on an ally, they're very dim, not as bright as the other effects from her glitter lance or her ultimate.
Her polymorph, on self cast, barely has any particles that are easily viewable by either ally or enemy. perhaps an increase there would make it a little more streamline with the bright, and bold visual effects her other spells have.
I do, however, wish that there was a recall animation and perhaps a little bit of voice over on her skills, maybe change up the quotes or something along those lines to put it more into line with the theme of the skin.
I wouldn't mind her skin being the usual purplish violet it is in the other skins. it's something about only Lulu having that skin tone that sets her out from the others.
Aside from the particle changes and the little tiff i have about the sounds, the skin itself is really well made aesthetically.