Twitter just recently changed the look and feel of their website to match their mobile apps. Now, Twitter is again planning to change it, making it look like a Google+ or a Facebook page.
From the image above, the new layout fills up the whole page rather than a vertical-only layout that we currently have. The profile picture is then situated on top-left corner of the profile with the whole header photo, much like Facebook. There is also tabs that categorizes your tweets, photos & videos, who you are following, your followers, favorite tweets and lists.
Your tweets will then be placed in a card-like layout, which is like Google+. It seems to fill up space depending on its size, whether if it is has photos or just plain text.
According to Mashable, Twitter declined to comment regarding the new-layout.