The YouTube embed capabilities have been expanded to automatically detect if the included video is a Short or standard video.
In the case of a YouTube Short, the Embed will automatically be presentend in portrait (vertical) mode instead of landscape (horizontal).
The automation also applies to users usign the "YouTube Latest Video" feature.
You don't need to do anything from your end, if Lnk.Bio detects that your video is a Short, it will automatically be converted to a portrait format.