It's "Fake DA/DR Manipulation" and it does literally nothing good for the website, except show a higher number in the Moz Panel and sometimes in ahrefs.
These are vanity metrics IMO. And since a lot of link buyers will rely on these for a quick inspection when buying links - a lot of unscrupulous will indulge in this practices.
All this so they can sell a few more links. Without outing, it's pretty easy to determine the target site from the above links. And you can see that target site has a DR of 44.
This has been around for a few years now.
The simplest technique is through "Redirect Notices" from Google or other similar sites. In the page you linked, there are 20,000 links with various redirect domains. So this gives them the necessary variation.
So for example, links such as the below are added to an obsolete Web 2.0 or to a blogspot or to a Youtube description or as a blog post in a shitty PBN.
maps.google.com.tw/url?sa=t&url=https://www.example.com
images.google.co.id/url?sa=t&url=https://www.example.com
images.google.com/url?sa=t&url=https://www.example.com
images.google.at/url?sa=t&url=https://www.example.com
maps.google.at/url?sa=t&url=https://www.example.com
images.google.cz/url?sa=t&url=https://www.example.com
maps.google.co.th/url?sa=t&url=https://www.example.com
maps.google.com.ua/url?sa=t&url=https://www.example.com
maps.google.com.tr/url?sa=t&url=https://www.example.com
maps.google.com.mx/url?sa=t&url=https://www.example.com
images.google.dk/url?sa=t&url=https://www.example.com
maps.google.dk/url?sa=t&url=https://www.example.com
maps.google.hu/url?sa=t&url=https://www.example.com
maps.google.fi/url?sa=t&url=https://www.example.com
These pages are then run through an indexing service. And ultimately results in a high Moz DA or a higher ahrefs DR. This is one of the reason why a Moz DA is an obsolete metric.
How to check?
1.Check the domain in Moz
2. Goto "Inbound Links" section
3. If you see a lot of "Redirect Notices" or links from sites like maps.google or plus.google or something - the DA has been manipulated.
4. Run like hell from such providers.