AMP[1] is a (somewhat maligned) Google 'standard' which encourages a 'thin' version of sites with minimal assets and fast load times so that Google can display them in a sort of iframe-like context without the user actually having to leave the Google site (part of why it's maligned). Most site's AMP versions are lightweight and bypass any login/paywall because they want Google to show the rich results of this page. I'm guessing this person is interested in you using the AMP versions of Reddit which may be lighter, zippier, and not require login. I'm not sure if it's possible for a third party to display an AMP page the way Google does, though -- maybe ¯\_(ツ)_/¯
[1]: https://developers.google.com/amp