You refer to iPadOS16’s new Stage Manager feature. Your iPad Pro 11” is reportedly fully capable of running Stage Manager with an external TV (typically 4K UHD) or computer monitor of up to 6K resolution.
Turn Stage Manager on or off on your iPad - Apple Support
Due to limitations of internal hardware, the new Stage Manager feature, introduced with iPadOS 16.1, is available for these models of iPad:
- iPad Air (5th generation)
- iPad Pro 11-inch (all generations)
- iPad Pro 12.9-inch (3rd generation and later)
Feature availability is usually limited by system hardware - CPU and available RAM being critical to some advanced functionality. iPad models supporting Stage Manager have an M2, M1 or A12X CPU (upon which the M-series CPUs are reportedly based) - with at least 8GB RAM.
This iMore article provides a good summary of the iPad Stage Manager feature:
https://www.imore.com/how-use-stage-manager-ipad
iPad models that don’t support Stage Manager are more limited - in that they can only use screen mirroring - this quite literally mirroring the iPad’s own display to an external TV/monitor. Given that the iPad has 3:2 aspect ratio, when used with a widescreen (16:9) TV/monitor, with screen mirroring you will see black infill-bars to the left and right of the screen (and possibly top and bottom as well). If the monitor stretches the iPad’s 3:2 screen image to fill the screen, you will obviously see image distortion.
In addition to screen mirroring, an iPad can use a connected monitor to just show video material at its native resolution. As such, a 16:9 movie can completely fill the screen of a 16:9 TV/monitor without distortion or black infill-bars - while simultaneously using the iPad’s own screen for other tasks.
The iPad User Guide provides details of connecting your iPad to an external display:
Connect iPad to a display with a cable - Apple Support
If using a display with an HDMI or VGA connection, will need suitable display adapter to connect to your iPad’s USB-C port:
- USB-C Digital AV Multiport Adapter
https://store.apple.com/uk/xc/product/MUF82ZM/A
- USB-C VGA Multiport Adapter
https://store.apple.com/uk/xc/product/MJ1L2ZM/A
If you have a 2021/2022 model of iPad Pro, for compatible monitors that support DisplayPort over USB-C or Thunderbolt3, you can also make a direct connection using an appropriate cable.