Please explain this graph part to me?

Attached are three images after I run a test. I do not understand what it is showing me. I thought the length of the “lines” is a representation of how long in seconds it takes to download, but apparently that’s not correct.

The big image is just for example to show how these images are freaking huge and take (it seems) a long time to download. Yet notice in the other two images that is specifically the favicon.ico file which is a tiny little thing, yet the purple line is still super long. BUT when I click on the purple line for that file the popup window shows it only took 13ms to download?!

Please explain this apparent discrepancy to me someone!
Thanks!

This is a general shot of some image loads:

This is the load line for the tiny favicon.ico file:

This is the popup window of details for the favicon.ico file:
web-test-2

@Mushu Can You share a test?

Content Download is a dark purple on the image.

From the popup You can read that TTFB have 8527ms this is time how long your server respond for favicon.ico.

You have a lot of that long requests, I guess that all of them are from your domain.

Look on the third part requests they are faster.

Matt Hobbs has an excellent (and thorough) article on reading waterfalls.

With HTTP/2, multiple requests can be in-flight and interleaved on the same connection which is what you are seeing and is probably leading to some of the confusion.