A thrust reverser of a turbojet engine nacelle includes mobile cowls which retreat with respect to a front frame while causing via cylinders the tipping of the shutters initially folded inside these cowls, so as to substantially close an annular stream of cold air, and cascades disposed around the annular stream which receive the cold air flow in order to send it towards the front. Scanning N2 times by a negative gradient also takes place, and the negative gradient scanning signal is collected during each scan. The system further comprises a graphical controller configured to magnify a portion of the visual content that is located at an approximate location of a base of the normal axis on the user interface screen.