Both are photoshopped. Look at the girl on the surfboard and the small wave passing behind her in both photos, they are identical. So in sequence of the two pictures - the tuna gets closer to the water and the whitewater behind it subsides, but the girl and the rest of the ocean remain frozen in time? Nope, photoshopped.
I am totally with you as to speculating why someone would take the time to do this, it beats me. Probably a similar motive to those trolling around an online forum trying to sniff out someone to call an a-hole or an idiot over a picture of a fish.