This is a really good piece! I think why it feels a little flat is due to values and composition. It lacks a bit of depth too (not much_) I would try to define whats closer and further away from the view point. (it alsodepends what you wanting to stnad out) The top of the smoke can go closer to the camera and can get darker or lighter. It also all kinda falls into the same tone, its all like the same dark grayish kinda vibe, which explains why the pink highlights make it look better. I would add highlights to more of the area to bring out the person. I would push the pink light and also add darker shadows to focus on the cigar and face. Overall this is really beautiful and well done <3 (also i would maybe try and mess with values a bit to differentiate all the colors.
Omg thank you so much!! That makes so much more sense and the paintover makes it look so much better, definitely going to make those changes when i get a chance!