Re: Page scroll stuttering
The new homepage "loading" behaviour follows a mobile-first approach.
A particular concern was how the new behaviour would affect users bandwidth and overall page loading time. If ALL the images are loaded in the raw HTML we are:
a) slowing the page load;
b) forcing users to download images that they may never see (specially for the articles further down the page), or in the case of mobile devices matching certain breakpoints, they would load an image that we would later HIDE in the CSS as don't want the image to show on those small devices this then means the image would be loaded as it was part of the document but would be entirely useless to the user.
To avoid this wastage of bandwidth (and avoid the slow page load) we opted for a lazy-load solution via JS, where images are not requested UNTIL the time a user has "shown intent" of seeing them, this is done via a JS function which determines said intent based on the users scrolling behaviour, the parameters for WHEN to trigger a given row articles image request are something we're still fiddling with.
This lazy-load technique means that the raw HTML can not contain the article images as doing so would defeat the purpose of the lazy-load enhancement (and bandwidth saver) and as a result users with JS disabled get no images on the majority of the articles.
If the page scroll is stuttering for you, my guess is that you're scrolling "too fast" OR experiencing poor network conditions. If you can provide us with your device details, we'll try to replicate the stuttering.