If you're shooting people, it's all about the eyes. Even if they are not looking at the camera or their eyes aren't even in the photograph, we, as the audience still need to feel the eyes. I'm going to see if I have some examples to illustrate my take on this. To be truthful, I was going to leave it as "It's All About the Eyes" with no text and just this one photograph.
So, you see I didn't just show a photo with engaging eyes...this eye tells a story.
Here's my example of straight-up engaging eyes.
In this photo you can barely see the eyes, but I think you can still feel them.
Bottom line, be aware of the importance of the eyes. Even this one...