I never said the second image showed a guard. To the contrary, I specifically say that the bottom figure is mounted. Obviously, that is Not Good. My point was that in that plate, Mair instructs the mounted figure to fight back, not to sweep. Perhaps an escape is implied after
the groin/face attacks, but Mair doesn't mention it (which he usually does in weapon plates, i.e. "and then withdraw from him by doing X").
Thanks for the color image, Chidester. Here is the full plate (in color): http://daten.digitale-sammlungen.de/~db ... &seite=580
Mair's text confirms that it is a type of guard, as that term is used generally in BJJ. Here's an idiomatic translation:
Top figure: "When both of you are on the ground, seize the inside of your opponent's right elbow with your left hand, push it up, apply your right hand to his left forearm, and spread his arms apart." The text also implies you should "press the weight of your chest into him" (see below).
Bottom figure: "If your opponent pins you in this way with his chest pressing into you, throw your right leg up over his back and your left foot up over his right leg, and in this way he will actually be trapped
." The Latin for the italicized clause is "actu is interclusus est" and the root verb is "includere: to enclose, imprison."
Top figure: "To free yourself, knee him in the groin with your left leg so that he loses his strength and is forced to release you."
Given that Mair explicitly states that the bottom figure's legs are used to trap the top figure, I don't know how you could call this anything but a "guard," and a clear one at that!