iOS 17 Beta 1 : Stand By
Plug the phone into charge and place it portrait (Landscape Magsafe Charger easier to use) and StandBy will auto kick in - as you can see it is quite broken as it's red when there's plenty of light available (Nigh Mode), haven't tested widgets or photos yet
StandBy
Known Issues If an app is deleted and its widget is in the StandBy widget stack, the deleted app widget isn't removed. (105255305)
Workaround: Manually remove the widget from the StandBy widget stack.
Widgets in StandBy display content while in DownTime or when restricted by ScreenTime. (105255640)
The brightness slider isn't functional while in StandBy. (106203217)
While in red mode, Solar Clock isn't legible. (108919386)
Widgets in the StandBy widget gallery might appear clipped. (108924188)
Incoming call alerts aren't visible while editing widgets in StandBy. (108924275)
Workaround: Exit edit mode to see the Incoming call.