Why isn't a new virtual connection almost instantaneous?

I’m away from home with a laptop I haven’t used for a while. I wanted to set up a virtual connection to my server to have access to some files. I created a new folder and set up the virtual folder sync to an established group folder containing about 100,000 files.

I was surprised to find that it is taking a long time to set up the sync. I imagine it is not downloading the files because that would defeat the point of virtual folders but what is it doing? This is a new empty local folder and the server presumably already has a database of all the files it has. So why is this not an almost instantaneous download of the folder structure from the server and I’d be up and running in a few seconds?

Nextcloud version 20.0.0:
Server Operating system Ubuntu 20.04.3:
Apache version Apache 2.4.41:
PHP version 7.4.3:
Desktop client 3.3.6