Here's what Jessie had to say about this scene when it was first released in 2014:

"That's right, it's the rest of the pieing alphabet with Cherry and myself! And this time, it's my turn to get pied! Cherry has some pretty inventive suggestions for the second half of the alphabet... Can you guess what she did for 'Z'?!"

Important note: This is an edited version of the original scene. In the original scene Jessie's boobs were visible during the pie techniques for X and Y. Those bits are edited out, to respect Jessie's wishes.