A tribute to Applejack's stellar performance in "Applejack's Day Off" perhaps? Or maybe they painted Derpy and removed her wings temporarily. I do see multiples of each characters in some of these pictures. It wouldn't surprise me.
Anyway, if you missed yesterday, an event is going on in Singapore right now with a gigantic storybook theme, complete with cardboard cutout ponies adorning everything. Check out a better gallery of the sets below!
Thanks to Chuan for the heads up!