For anyone with a keen eye for detail, the first session of free practice on the Friday of a MotoGP event is always fascinating. FP1 is where riders will try new parts, or more experimental setup changes. Helpfully, those changes are almost always tested back to back with the standard setup, for the sake of comparison.
Even more useful is the fact that the first run of the day is done on the bike which the rider has been using so far this season, to give them a quick reminder of exactly how the bike feels and set a baseline. They then jump onto the second bike (using the same tires) with the altered setup or new parts. It makes spotting differences a good deal easier.
When those new parts are updates to the aerodynamics package, spotting differences becomes a piece of cake. Fortunately for people like me with poor eyesight and addled brains.