I'm very surprised this maneuver wasn't assessed in any of the answers. It actually does look like they're practicing a touch and go maneuver. The tires aren't producing any smoke and the flaps are positioned at a T20 so its both a landing and takeoff configuration. This is also a very late position for a 747 to be landing on an airstrip of this size. All evidence, for me at least, suggests a touch and go.

The fact that its airforce one aswell and they'd likely be practicing different techniques and training pilots.

Taking the lack of air distortion from the behind the engines, it could be because the photo is extremely grained/blurry to begin with and the flaps foiling the air to the ground rather than directly behind the engine.

My only other guess is they were practicing late landings.