An airplane always moves forward (like an arrow) so the pitot tube is mounted so it points in a forward direction. Pitot tubes don't swivel. You may be assuming that the black disc at the base of the pitot tube mast swivels in some way, but it doesn't. What is movable on the pictured device...
Have a look at the picture in the wiki. Notice that it is mounte on its own little wing on a swivel so it always points into the wind (at least in the pitch axis).
The wikipedia picture was not the best example of a pitot tube.
The picture in wiki is a pitot tube with an angle of attack...