[pbh101]

Visible, but not necessarily readable: "This does not necessarily mean the user saw the page content" [1]

[1]: https://sites.google.com/a/webpagetest.org/docs/using-webpag...:

[JoelSutherland]

The link I added has a filmstrip view where you can verify that this isn't the case. Alternatively visit the two sites yourself! The multi-second difference is perceptible to a human being.