Here is what I was able to gather from this limited amount of information:
1) The skull reminds me of "The Day of the Dead" from Mexican culture. It seems to me like it might be a gang similar to Los Carnales.
2) The top of the skull has iconography that looks very similar to The Brotherhood. The Brotherhood and Los Carnales had close ties to one another, and you can even see a cross (Los Carnales' Symbol) within The Brotherhood's wolf symbol.
3) I am thinking that gangs within the new game might have a similar structure to The Syndicate in SR3. In other words, maybe the main gang is an equivalent to Los Carnales and the equivalent to The Brotherhood is a sub gang or "set" that falls under the umbrella of this new gang. It is possible that the Luchadores might return to some extent and fall under this umbrella as well.
4) The skull has a tear tattoo, which signifies that they have killed someone or might be seeking revenge for the murder of a loved one. This might tie into their backstory, if they have one. The tattoo has multiple meanings, but these ones stuck out to me the most.
5) The color scheme reminds me of "The Joker" from "The Batman" series, which is somewhat important because South Park made an episode about "Mexican Joker", so this would tie in perfectly. I think it would be a great reference, as well as provide some craziness to the game. Imagine a terrifying, insane, Mexican Joker as the leader of the gang.