These are 2 versions of the YouTube banner that are Live right now!!!
If you're seeing one, clear your cookies and open YouTube again, if you don't see it then try again, I guarantee you will see these two different versions of YouTube banner. I just did.
This is called A/B testing, used to determine whether a parameter change has an effect on the population.
Apparently Google is conducting a secret experiment to see whether
- people like the Google branding, do people use the service more if they see it's Google owned
- or people hate the Google branding, do people drop out if they discover Google owns everything