What causes different application download speeds when connecting via remote desktop from different locations?

Question

Remote access

Interesting fact noticed.
The user connects to a remote desktop through a local network in the office and starts the application. It loads in 1 second.
If the user connects to the office via vpn and then - remote desktop, launching the application, then the application is loaded in 10-15 seconds. At the same time, there are no brakes, no delays in the system.
What could be causing this? After all, only a "screenshot" of the screen is transmitted to the remote computer, all operations take place on the server.

Answer 1

Not a screenshot, but a real-time video + time for the welcome bows of the computers.