A new report mentions that Google will start using a new logo for the browser version of YouTube. It is said that this logo will be consistent with the mobile apps. As you know, the web version of YouTube now has a slightly different logo compared to the mobile versions, so this change was long expected.
It seems like Google will gradually start rolling out these changes for Youtube.com as the new logo seems to be currently under testing. With this change, Google will simply display an icon for YouTube rather than displaying the name in its entirety, as you can see from the screenshots above.
YouTube has undergone a couple of changes over the past few months, most notably with the inclusion of the new Music Key paid subscription service. A recent report suggested that the video streaming service could get a radio feature soon which would tailor playlists based on the video that the user is watching at the time.
Source: Google Operating System