Helmet-cams are always imperfect — mounted a few inches above or to the side of a driver's eyes. Lucas di Grassi drove with one eye covered by a camera to let you see exactly what he sees driving an F1 car.
Moreover, he's driving around the high-speed curves of Spa-Francorchamps, and he's in the wet. The last time he tried this, Lucas explained why we'll only see this on test runs.
"I had to drive with only one eye open as the camera was blocking my other eye, quite tricky.
We haven't seen the camera set-up from the outside, but we can assume it's more high-tech than when Bruno Senna drove around Spa holding up his Blackberry.
You can see the 17-minute, unedited version of this video here.
(Hat tip to ncasolo!)