New action window??
 

I've noticed a new window in the UI on Test. It's quite small and appears top center over the compass window. I can't move it. The tooltip that appears when I hover over it says "Open House Window." Clicking on it does in fact bring up the House window. There is a small arrow on the right side. Clicking the arrow expands that part of the window to display a large green arrow. The tooltip for the arrow reads "Leave House."

Not sure how long this has been on Test. I haven't played there in a while.

House Window (was:New Action Window?)
 

Now that GU66 has gone live, I have a better idea what this does. Clicking the main part (the cottage icon) opens the /house window. Clicking the arrow on the right expands the window to offer options to 'Leave House' and 'Enter/Exit Decorator Mode'.

It seems to work as it is supposed to, but I haven't checked it on a default UI. In the default location it does slightly overlap compass window on the left. It is moveable; the target is just very small.