This is Standing Doggy-Style. In a venue where lying down is undesirable, this is a great position to practice. It is highly advised that the receiver find a suitably secure object to hold onto or balance themselves against; this will allow for a more enjoyable experience, faster thrusting, and less likely-hood of falling over.
For variation the receiver should try spreading their legs apart or bringing them together. However, the farther you spread your legs the deeper the giver is going to have to squat to gain access; say hello to burning quads. To overcome height differences, the giver should try squatting, or the receiver should be given something to stand on.