I don't know if this was answered earlier...the reason they call Marcos Angeleri "Mambru" is due to his emo/metrosexual haircut/overall style, which is typical of a recent argentine boyband called "Mambru". Clearly he looks like the guy in the far right Angeleri
Heh he looks like Russell Brand there. We're used to seeing him with his hair tied up and with the band around his forehead.