Comment 3 for bug 1445540

Clarification: By decorations I mean the "physical" window extents and not shadows.

AFAIK we have no plan to allow for client-side shadows (ie. rendering beyond the physical snapping extents of the window).

Of course Mir can't know if you're painting shadows or not. Just your window placement will look wrong if you do that bit yourself.

Server-side shadows will look more consistent (in size and gradient) and allow us to do proper 3D shadows in future too.