Revealing mistake: In the Milk River scene, you can see the cherry on the sound stage they are recording on.
Suggested correction: This has to be more specific. Saying, "you can see the cherry on the sound stage they are recording on" is too vague, because there are multiple cherries that the three of them pass while going down the river (and more scattered around the Land of Milk and Cookies). None of them looked off to me, and I couldn't find anything that resembled a sound stage either. If possible, someone please explain.