This option will only work together with fullscreen_new_window.
This is some relic in documentation of tinymce - default value is false (no new window) and you can set fullscreen mode to open new window with false but both work fine in current versions of tinymce. Why did they stop using the old way? To get around popup blockers (in IE)... like in plugins (dialogs) are using floating DIV layers instead of popup windows if default is not changed to modal with dialog_type :"modal".