http://i.imgur.com/SnGCP4G.png
On the screenshot above there are 2 windows of xfce4-terminal opened on the same machine (FreeBSD 11x64), but the left one is opened in xpra (via ssh connection to xpra server on localhost).
It looks like xpra's window is scaled down: smaller fonts everywhere and even smaller favicon on the window.
Two options:
this ticket has been moved to: https://github.com/Xpra-org/xpra/issues/1562