Dog Moon
Adventurer
I want to say that both are fine when appropriate, but I'm not sure that most books would be considered as appropriate. Most of their books seem to be general in nature and general should not contain such art.
Now, if they made a setting book in a dark, gritty world, then I do believe that it would be appropriate.
Now, if they made a setting book in a dark, gritty world, then I do believe that it would be appropriate.