This must be due to the different cooling configurations running on the left and right sides of the sidepod. More heat and they look to run a shorter chord length on that side of the car. Very interesting!
Even though it looks like it would create differential downforce on the left/right portions of the wing, it probably ends up creating more symmetrical downforce because of the interaction of the wing with the hot air coming out of the sidepod cooling vents.
I love to love Senna.