You might have it wrong, or typed your glitch wrong.
-n Open window minimized
-x Open window maximized
-p Picture Window
+n minimize box in titlebar
+t Show titlebar
+x maximize box in titlebar
if you wanted a Picture window with a titlebar, and the min/max buttons, and make it sizeable, and have it open The command you want is:
/window -np +nstx @Window
but all those features besides the PicWin are defaults, so all you really need is:
/window -np @Window
hope that helps, if not, then explain your problem in better detail.