That picture is a very good example of what NOT to do! Far too cluttered and too full of reflective surfaces for a good stereo image, there is also a good chance some of the kit inbetween will rattle at certain frequencies as well. It is a bit difficult to see but the whole shooting match seem far to close to the back wall?
Most of us have to compromise for monitor position however and my Tannoy 5a's are on wall brackets, not ideal but at least they have a big slab of absorbent foam between them and are firing over the top of 2 monitors and angled down. So long as one adopts a good, upright posture, the tweeters are firing into #1 and #2 lug.