How do I shake things up?

I've been playing Live from Bikini Bottom and have finished most of the items on my todo list.

There is one task I can't seem to complete: "Shake things up!"

At first I though I could succesfully shake by useing the arrow keys to tilt the island. This, however, only seems to have dropped a few more items.

I've also tried picking up all the characters and vigorously thrashing them about, but to no avail.

I feel like I've exhausted all options. How do I Shake things up(!)?

For reference here are all the items I've collected so far, though none of them seem to enable me to "Shake things up".