I didn't know which one to go with, but I liked both individually.
( Fanon idea )
I imagine Sombra can't help but get very 'passionet' almost kinda worked up when he plays on his organ ( XD it makes him feel empowered and sinister ) so in one he's drooling a little, just to make him look more like a beast, and in another he's not.
Also, this was inspired by this lovely piece [link]
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King Sombra © Hasbro