I only found it's a book when I noticed the tentacle was holding it. The way it interferes with the other tentacle behind it makes it unclear. Make that obvious and you're all good - for a book.
Magazines are not rigid like books, you can't hold them up with one hand or whatever appendage you're used to read with, and it takes a giant leap of faith to hope that at least one viewer will recognize it as Playboy Magazine XD

I really like the creature's head. Maybe the upper left eye needs a little fixing, nothing much.

A little disturbing but I still like it.

I think one of the problems with the book is the angle. The bok is opened facing straight backward while the alien is off to the right. I think the book should be facing towards the alien's face.
Also, the color of the book could be dark instead of so similar to the water.

 Thanks for the comment and critiques. And yes, that's supposed to be a Playboy Magazine, but I am not sure how to make it look like one. Can you help me? 

I was even thinking to detail the purple water but after working on this for an hour and a half I just decided to not to do anything but post.

Pretty funky, in a good way :)

Nicely done.

Is that a book? Not very readable.

I like the colors and the shading. Good job.