Is it just me or is this new trend weird?

Why are people uploading pictures of themselves to include with their book reviews over at Amazon?

 

As I was getting ready to update my reviews at Amazon I noticed this strange new trend. See this book page to see what I mean.

 

I can see posting a picture for a product review where you're actually showing the product but to upload a selfie just to upload a selfie? That strikes me as a little bizarre.

 

Would you do this? Does it gain likes or something? I can't for the life of me figure it out. I suppose I could ask on the forums but I hate that place.