That frame you are seeing is the AXInspector.
Calabash iOS requires that Accessibility be enabled to work. I am not sure what moved the AXInspector to the corner of the Simulator.
The easiest way to remove the AXInspect is to use the iOS Simulator > Reset Content and Settings menu item.
WARNING Resetting content and Settings will remove any installed apps and change all settings back to the default.
Alternatively, you can open the Settings.app on the simulator and disable Accessibility.
NB. The 0.9.169 release of Calabash iOS gem will enable accessibility automatically and hide the AXInspector.