It tells you that you have a unique fingerprint.

It is not telling you that the test site has never seen you before, because the eff isn't storing your fingerprint for later analysis and tracking

It could actually tell you about which real tracking vendors are showing you as "Seen and tracked" so it's pretty annoying they don't do that.

If that site shows you as having a unique fingerprint, I guarantee you are being tracked across the web. I've seen the actual systems in usage, not the sales pitch. I've seen how effective these tools are, and I haven't even gotten a look at what Google or Facebook have internally. Even no name vendors that don't own the internet can easily track you across any site that integrates with them.

The fingerprint is just a set of signals that tracking providers are using to follow you across the internet. It's per machine for the most part, but if you have ever purchased something on the internet, some of the providers involved will have information like your name.

Here is what Google asks ecommerce platforms to send them as part of a Fraud Prevention integration using Recaptcha:

https://docs.cloud.google.com/recaptcha/docs/reference/rest/...