I had a feeling that might be the case. I’ll have a chat with @dan and @ben to figure out what we should be doing here.
It has a few interchangeable names but generally we refer to it as the project browser. You could also use project navigator or page list.
We’re aware of the “mark as changed” and “mark as unchanged” menu items not working correctly. We’re planning a larger overhaul of publishing in Elements so we’ll get them fixed up then.