What happened?

Here's a simple description of an action. But there's something a little odd about it.

The Gronckle opened its evil, crocodile eyes.

In this snippet, Cressida Cowell doesn't say the Gronckle looked evilly. She says the Gronckle opened its evil, crocodile eyes.

How are these two ways of describing the action different? 

Let's try our own version.

Count Snardu bared his white, pointed teeth.

Describe a simple action.