Breathe BAM.
At the risk of getting killed: 8.4 isn't that bad if people are voting on what they think of the paintjob as opposed to the name of the painter. I agree that Natalya has mad skills and that the Venetian lady is gorgeous. But she may not be everyone's taste. Just as there are thousands of different artists with their own style, there are also thousands of viewers who have their own idea of what the rating system means. These things tend to balance out with time.
I don't mean to be taking away from your point, I'm just offering a different viewpoint. Maybe I see it differently because I am not a recognised name by any means, so I'm pretty happy with whatever score people choose to give my work.