You can connect Pixels with DisplayPort alt mode (8 and higher) to an external display and it will work. You get a desktop environment and can run all your installed apps in floating windows. Need to enable developer options though, in the future you wont need to. You can't run Linux apps in a good and easy way yet. A working desktop mode for Android apps is the base to build an environment for desktop applications in the future. Want to support Fedora and (if we're reaching for the stars) Windows ARM as potential platform targets. You can use the Linux Terminal app and enable GUI to use a virtualized Debian environment with GUI apps. We did it with desktop Chromium before and even some DE's like GNOME. It's a very experimental developer option and breaks even in very basic use right now. Doesn't work through VPN either. Upstream will improve this as well.

Would be sweet to just dock our phones and let it rip on a big screen/ mouse/ keyboard. LFG