Shot Notes
This beautiful sunset appeared through a misty cloud at Goolwa Beach in South Australia. I had positioned myself so this surfer would walk in front of me to produce a silhouette and make the shot. Unfortunately as she approached she saw my camera and put her hand over her mouth thinking she was about to ruin it. I tried to explain it was OK but the moment was lost. Fortunately I had captured a body surfer earlier so I could Photoshop in his head and shoulders. 
Split toning was also used to create some extra colour.
Now that you mention it I can see a slight ripple around the head in the shot. Perhaps the entropy rates of the two photo’s didn’t match and that confused the compression?
WordPress/YAPB uses fairly high jpeg compression. I have seen similar artefacts in high contrast areas even with single photos here and here.