Mamazota is a colloquial and somewhat provocative term in some Spanish-speaking regions, often used to describe a woman who is extremely attractive or curvaceous.
In the context of this song, it's used to emphasize the singer's strong physical attraction to the woman, highlighting her striking appearance and confidence. While it can be seen as a compliment, its use is informal and carries a strong connotation of physical appeal.
Xavi spends the first half of this song trying to get someone into a car. He opens with logistics rather than romance: "Y te mando al chofer" (And I'll send the driver for you), then "Me sobra el papel y te quiero ver" (I've got plenty of cash and I want to see you). When she plays coy he calls it: "Ya no te la juegues de santa" (Stop pretending to be a saint). The chorus is where the title lands, and it is about as subtle as a car horn: "Estás buenota y eso se te nota" (You're hot and it shows). He notices the skirt, and the hair down to her waist, and decides she looks better in person than on Instagram.
The second half turns possessive, which is the more interesting move. "No me gusta que te miren" (I don't like it when they look at you) is followed immediately by "Aquí traigo una corta para el puto que se arrime" (I've got a handgun for the a**hole who gets too close), and the flirt becomes a corrido. Luis R Conriquez shows up for the call and response every regional Mexican fan knows: "¿Compa quién?" (Buddy, who?) answered with "Su compa, Xavi" (It's your boy, Xavi). Charming, then a little alarming, in that order.