The episode begins with Pinkie Pie being invited (read: begging through 17 letters to Prince Rutherford) to the Yaks' Yicksluberfest. Pinkie arrives as the Official Friendship Ambassador to the Yaks… (More)
Repeat from the EqD, Animation Magazine did a “Day in the Life” of Studio B, which of course is filled with pony related stuff. Original article can be found here. I think this image is all there is, but I could be wrong.