I'm just gonna guess here, but the reason they're stuck on the island is because Fluttershy is to... scared to fly over the ocean, and Rainbow can't carry her back to shore/doesn't want to leave her alone on a stranded island xD just my idea though
Wonderful picture btw, I saw the original piece before, and thought it was hilarious, this is even better
This is awesome! The only thing I don't understand is how two pegasi could be stranded on an island... but everything else is great. I think if you blurred the tree and pony reflections a bit, the water would be perfect.