Great find! I thought about the same thing recently…after checking out the mobile site in my opinion this kind of mobile design takes the same approach as designing for an app.
I’d say since the color of the navigation isn’t overbearing it works. If the nav were black or some other color that screams for my attention it would distract me from the actual content of the site.
The only problem I had was that I didn’t know the difference between the home icon and the second icon. I ended up in the same place on the site, but the overall execution doesn’t hinder how I use the site.