The normal solution would be as follows:
export DISPLAY=:0.0
/usr/lib/vino/vino-server &
But what happens if that doesn't work? I haven't been able to find much documentation about how to find the list of displays and how their numbering works in Xorg.
Sometimes you'll get this error when trying to restart vino:
Cannot open display:
For some reason my display is not on 0.0........