Actually... a couple of times at practical/field/tactical rifle matches, I've encountered stages that required the shooter to fire from the weak shoulder. Nothing was said about which hand I had to use to pull the trigger (shooting prone from a bipod). So I ended up snuggling the rifle up to my left shoulder and reaching over to finesse the trigger with my right hand... something similar to what is shown in the picture. Though for some reason I'm guessing thats not how/why they ended up shooting that particular pic...