Today you'll start to notice a new feature when scrolling through banks of images, such as the galleries below entries, photos, and videos, as well as the newsfeed on the home page.
As your scrolling loads new banks of content, the URL in the address bar will occasionally be updated (probably when you take a pause from scrolling). This will enable you to use the back button to navigate back up the page, as well as the refresh button to move directly to the content that you've landed on.
You will also notice that the scrolling and loading experience is now faster, with less interruption.