Not sure if this was intended but - I like the way the reflection in his glasses and angle of his head makes it seem he is looking down on the world, the cross in the background emphasises the effect somewhat..
Whilst sunglasses hide the wearer's eyes, they can show you what he's looking at, and in this instance he is proclaming his beliefs to someone standing over him.
He is a gently spoken man explaining that Islam was created when the Angel Gabriel explained everything to Mohammed. The things you learn when you dabble in photography!
I spent two years living in the middle east (Saudi for one year). I discussed Islam with many of the people I was working with and they believe that Mohammed was the second prophet. They recognise Jesus and the cross etc., but believe Mohammed came to further advise and guide. The fact that the christian church does not recognise Mohammed is the root of the disharmony between Muslims and Christians.
Hence the fence / cross behind the Imam is a symbol of the christian faith being behind islam (time wise), Him looking down is like the early religous artwork were the powerful always looked down at thier subjects below, and the reflection in the glasses pulls it together as it shows the listeners / followers.