As I said in an earlier post, I work as a reviewer. Clickaway, let's just say you got a model release for the guy in the pic, all you have to do is just blur or clone out the logo etc.
As to the pic itself, it's not evident what the guy is doing. Pics that do well are those which are posed, good lighting and sharp.
A lot of people just submit flowers, sunsets, even ununexpected people of their backs. (Watch out, it's not safe anymore if you see someone with a camera anywhere! hahah) You can submit and might be approved but it just won't sell. And lots of people are lazy with keywords. A stock photo company can do all the advertisement re their pictures but ultimately, it's your keywords which are important. And I don't mean keywords spamming.
If anyone here would like to start earning some extra pocket money, one example of what people or companies will want to buy is to look at the pictures/frame department at IKEA.

See the quality, the lighting, the subject. Start from there and you will soon see what the demand of particular pics are.
Yogi