The hardware used for the test included a MacBook Pro with Windows installed, a 24 inch ASUS monitor, a 15 MBps internet connection and a Phantom v640 high speed camera that can capture up to 2700 frames per second at a resolution of 1920 x 1080.
"Why does allrecipes.com in the potato gun sequence appear at once, and not the text first and images second? And why does it appear to render from bottom of the screen to the top?"
Chrome sends the rendered page to the video card buffer all at once, which is why allrecipes.com appears at once, and not with the text first and images second. Chrome actually paints the page from top to bottom, but to eliminate a shadow from the driver board, we had to flip the monitor upside down and set the system preferences in Windows to rotate everything 180 degrees, resulting in the page appearing to render from bottom to top.
When capturing a screen at 2700 frames per second, it reveals interesting information such as which parts of the screen load first. Google, in the description of the YouTube video below have explained why all these certain conditions have happened. Take a look at the video below to see the tests, then click the video to see the long description of how it all works.
The video below shows how it all works...