Page is Interactive?

[adroit24]

I read this definition of Page Is Interactive metric from below:

https://github.com/WPO-Foundation/webpag...ractive.md

Question: I thought this metric would mean I cannot scroll up and down on the page or cannot click on any links on the page (based on the results I have below). But I am still able to do all of that. Then what exactly does having all of the red on Page is Interactive mean?

https://www.webpagetest.org/result/18021...c844c1534/