The three-quarter Nelson is clearly illustrated in the picture. Note that Farmer Burns has thrust his right arm under the opponent's right arm as in the half-Nelson, but he has strengthened the hold by grasping his own right hand with his left to secure greater power.
Also note that Burns has his body CLOSE TO HIS OPPONENT. This is necessary in all Nelson holds in order to prevent side-roll or head-spins by the opponent. Farmer Burns' knee, leg and body positions are all strong and powerful.
By working fast, following the opponent closely with his body as he turns over, Burns can secure a fall with this hold alone, but it must be done just right, for the slightest loosening or 'play' will allow the opponent to get away.