Why do I have 2 host Mac desktops?

I'm running Parallels v10 and I have two Mac desktops. Typically, I use my Magic Mouse and swipe with two fingers to go back and forth between my Mac desktop and my full-screen Windows desktop. Recently, I discovered if I swipe past the Windows VM I have a second Mac desktop. It has all the same icons as the other but the background is different.

Did I accidentally turn on some feature or something?