Pinkie Pie got sick (maybe from baked bads) and she's been alone in her quiet room with no forms of entertainment whatsoever, and she can't have any fun. Twi, RD, AJ, and Rarity are busy with work (or shopping, who knows), but Fluttershy isn't. So she decides to step out of her comfort zone to try and entertain Pinkie (while dragging Angel along). Seems that entertaining Pinkie has been a success.
EDIT: Whoa, this is the first pic I made that got 2,000+ favs in a long while. Thank you guys so much! EDIT 2: This is my most favorited picture now! Thank you all so much!
MLP:FiM belongs to Hasbro and was created by Lauren Faust
If you have to be that picky. I wouldn't have even noticed that tiny detail if you hadn't pointed it out. If it makes you feel better can't you just imagine that Spike was the one who made the drawing?
Well, maybe picky isn't the right word. It feels like the same sort of thing that if you have close to everyone it annoys people. If you have a CMC drawing with only Sweetie Belle and Scootaloo people are naturally going to comment "Where's Apple Bloom?"
Maybe the artist just forgot about Spike. IF that ruins the pic for you than I'm sorry, but the main focus of the picture isn't even the card anyway.