Please label your axes. The units are not obvious. I think the x-axis is pixels, where 0 is the top of the viewable part of the browser, and increases downward

Please label your axes. The units are not obvious. I think the x-axis is pixels, where 0 is the top of the viewable part of the browser, and increases downward, but it took me a long time to figure that out. (My initial guess was milliseconds into a page view, but that makes no sense since I assume the y-axis on the second graph is seconds into engagement.)