I tried something similar like this to render thumbnail of websites (at a very small file-size). E.g. https://twitter.com/yvoschaap/status/1446397003316047872
That looks like a Web Archive (WARC) and a PNG screen shot. I think you can make a screenshot with CasperJS. The WARC can be created by wget.
Source?
Wikipedia says: https://en.wikipedia.org/wiki/Archive.today#:~:text=Web%20pa....
So I assumed they don't use it but idk for sure.