There might have been a way to digitally zoom while viewing on the app.
You can kind of do that afterwards if reviewing recorded photos or video on a computer.
The Mavic 2 Zoom big selling point was/is the first mainstream drone with a proper optical zoom.
The Mavic 2 Pro has a larger sensor similar to P4 and you can go to a cropped in view rather than actually zoom with minimal loss of quality.
Not sure if some versions of P4 could do that too.