Composting Surprise

I started composting about a year ago. I put together two bins. One was "hot" and one was a holding bin I planned to start cooking when the other bin was just about done. Above is a photo of the holding bin. The surprise is that the holding bin is just about done - without me trying to get it "cook," by adding nitrogen and stirring and keeping moist. That plastic cup says "compostable" - but as you can see, it hasn't. I'll bury it and try again.

 Here is finished compost from the pile I thought was the only one really "cooking."

Now, it starts all over again.