Connecting iPad mini 6 to a display via USB or HDMI

USB-C Digital AV Multiport Adapter

https://store.apple.com/xc/product/MUF82ZM/A

The product description does not include iPad mini 6. It is only mentioned in the compatibility list. I don't think this adapter makes any difference at all in terms of resolution and scaling.

In the screenshot shared above you see that SDR is active when connected with the DisplayPort over USB-C cable. I obtained the Belkin adapter AVC002 to test if HDMI over DisplayPort Alt Mode would activate HDR.

The result: HDMI does not make any difference. (I am now working on the question whether the U2518D's "Smart HDR" feature, which is active, is somehow different from the common use of the term "HDR".)

To my delight, I found that Prime Video movies extend to the full width of the display. (As I am not currently an Apple TV+ subscriber, I have not yet tested if that's also true for the Apple TV app.)

The USB ports of your Dell monitor are not used to connect video. This monitor incorporates a USB hub to facilitate connection of USB peripherals.

Agreed. They are not comparable to USB-C ports on modern displays that support USB-C Alternate Mode.

Available video inputs are HDMI and DisplayPort.

When connected with a Cable Matters 201336-GRY-1.8m DisplayPort over USB-C cable, the screen of the Dell display has black borders to the left and right. I am not aware of Apple-official resolution specs for an externally connected display. So I have to assume that the 2266x1488 resolution of the iPad mini 6 is being mirrowed 1:1 onto the middle of the Dell'ss 2560x1440 screen.

I then tested with this video. Unfortunately, video playback in YouTube fails when I select a different resolution.

"Something went wrong

Tap to retry"

To connect your iPad mini6, you would be best advised to connect the iPad to the monitor using HDMI - for which you will require a sustainable adapter.

Do you know what the adapter does? I would like to understand why it is needed and why HDMI is preferred over DisplayPort. The sentence "..., try a different HDMI cable or adapte0.r" also seems to indicate that HDMI is preferred somehow.

Another option I am now considering it to use a dock. I just don't know why – I mean, why is a a cable not enough?

Unfortunately, video playback in YouTube fails when I select a different resolution.

I tried this again, selecting different resolutions – this time the changes do occur, but I don't get 1440p60 to fill the Dell's entire screen.