Thanks, hayito ... this is one of the few concerns I have about Tesla design.
Tesla uses a 'frameless' design for the front door windows ... the window glass swings with the door, but the weatherstripping stays with the car body. It looks great ... especially when the doors are open and the windows are down, but the devil is in the details. Getting the window glass that swings sideways with the doors and moves vertically with the power opener to align with the weather stripping is difficult at best and as your picture demonstrates sometimes fails completely.
Further, there is only one seal to separate the outside from the inside ... where the glass contacts the weatherstripping. Unfortunately, this point of contact is along the upper edge of the window, which is close to the driver's and passenger's 'outside' ears. This is why frameless doors tend to be noisier than framed and especially if there is a problem with the glass not sealing against the weatherstripping.
It's a small matter compared to the overall value proposition of owning a Tesla, but it is growing in importance in my decision to trade our current SUV for a Tesla Model X:
Mercedes-Benz is guilty of over-design and there is no better example than how they design their framed doors and weatherstripping ... three seals compared to one for the Tesla, which is why the doors close with a 'thunk' and wind noise is essentially eliminated. I can't expect the same quality in a Tesla ... by design.