Cover/privacy guard for underneath canopy?

Is there anything like a retractable screen that can mount between the bed rails which can be used to hide items in the bed area from sight when the bed is covered with a canopy?

 

You mean like a tarpaulin?

 

I've usually got camping gear in the back of mine so it kinda looks like a homeless guy lives back there.

 

I thought about a tarp, that would be my last ditch resort as I'd likely want to suspend by the rails so it's not obvious when stuff is back there.
I'm currently using a tonneau but strongly considering getting an Alucab for better cargo storage.

I suppose I could possibly just install blackout covers over the windows and get one of those rear view camera mirrors so that I can still see directly behind me?