This was a nice watch, kinda gave me a Muppets Tonight-esque vibe. In fact, the whole thing felt like it was meant to be a muppet show. What I enjoyed the most was the behind-the-scenes stuff with Bert & Ernie. I'd honestly prefer if they focused more on that in future episodes. Also enjoyed Cookie Monster as Elmo's sidekick + Herry Monster being in the band.
I do feel like the whole thing was way too rushed given they only had 15 minutes. And the Jonas Brothers were pretty boring here as well. I really enjoy the concept but I hope it eventually becomes more plot-based and gives a better look at what's going on behind the curtains.