Most probably it's not the photographer but the publisher that dicks around with these. If you check out the DailyMail (don't forget to wear gloves and a mask) you'll often see that the photos illustrating the sidebar (and sometimes even the ones in the main story of same) are mirrored. Now and then they even place the non-mirrored and mirrored next to each other to make it seem likes there's two different photos! I presume this is done by the compositor to 'give balance' or whatever to the page - perhaps photos down the right side seem better when the subject is looking left, into the page, rather than right, off the page. The photographer merely takes a decent snap and is then left out of the loop as it is twisted, clipped, cropped, darkened, etc, to suit whatever.