Check the privacy policy: https://p2p.mirotalk.com/privacy
E2EE usually implies that your connection goes through the company's server(s) before reaching your contact during communication. With Mirotalk, your connection is P2P. You connect directly to your contact. Your video stream never goes through the company's server. And the connection is still encrypted of course.
So yes, your stream is encrypted. Honestly, if it wasn't, no way they'd be in business as encryption is probably the bare minimum nowadays when it comes to any kind of communication.
From what I understand Nymvpn uses 2-hop connection, aka your data goes through two of their servers before reaching its intended destination, versus 1-hop with most other VPNs. It's more private, but you'll sacrifice speed as a result of having to go through at least 2 servers. They even have a 5-hop mode, which I don't know, probably would be slower than tor xD