Changing display settings inside the View desktop is deliberately disabled inside PCoIP sessions by our agent as it would have no useful effect - all display settings are coming directly from the client configuration and are always applied when the client connects or sends updated information. If you look inside the pcoip_server log file on the VM for your connection, you can see the details sent down. For example, on my setup (windows client):
02/19/2014, 08:39:18.192> LVL:2 RC: 0 MGMT_IMG :Native resolution of the client display 0 is 1600x1200
02/19/2014, 08:39:18.192> LVL:2 RC: 0 MGMT_IMG : Display 0 added using native dmt: resolution=1600x1200, origin=(0, 0), rotation=0
02/19/2014, 08:39:18.192> LVL:2 RC: 0 MGMT_IMG :Native resolution of the client display 1 is 1600x1200
02/19/2014, 08:39:18.192> LVL:2 RC: 0 MGMT_IMG : Display 1 added using native dmt: resolution=1600x1200, origin=(1600, 0), rotation=0
02/19/2014, 08:39:18.192> LVL:2 RC: 0 MGMT_IMG :Client display 2 is not connected
02/19/2014, 08:39:18.192> LVL:2 RC: 0 MGMT_IMG :Client display 3 is not connected
I'm not familiar with how the Mac client decides on the monitor topology, hopefully someone else can comment on that.