It is important to remember that a snooker is completely different to a total snooker, in both definition and application. The definition of a snooker is only applicable following a foul. 

When assessing a snooker the distance between object ball and cue ball is important. When the cue ball and object ball are a table length apart, the points of finest cut are almost the extreme sides of the object ball. As the distance between the balls decrease, the points of finest cut become closer together. When the two balls are touching the two points of finest contact are the same point. Hence a player cannot be snookered on a touching ball.