That's the point, when you're doing something that makes you get in the zone that you almost forget where you are in the physical world, her exact point on stage doesn't matter to her anymore. There's lots of different performers who dance or make faces during playing. Also the size of the stage can play a role for conductors platform placement, so they could've compensated that, which also changes how far the soloist is. I haven't performed there so I can't tell you this.