Is this plane landing or departing?
The plane is probably taking off.  The flaps are hard to see but they don't quite look to be extended enough for landing (Looks like flaps 20).  On a 747 they extend to around 45 degrees (flaps 30, but they curve around more than that) for landing and have a huge, unmistakable profile.  Further, we know it's KBFI and we know the plane is on 31L from the photo.  Looking at the area we can deduce... (click for bigger)

...that the plane is about 3500ft into the runway proper, and 4500ft if we count the displaced threshold (and just off the ground) with the face of the southmost Jorgensen Forge building visible in the background (along with the green GA hangars).

At 3500-4000ft into the runway, hovering over the last markers in the TDZ, this seems quite late to be a landing.  It might be a very deep float, but I would expect more precision from an Air Force pilot flying the CINC around.  Air Force One is heavier empty, but probably overall lighter than a loaded 747-200 (and has powerful engines), so a 4000ft takeoff run for a light 747-200/VC-25 is sensible and probably more likely than an extremely late landing.
The flaps are more than minimum for takeoff, but seemingly less than normal for landing. Maybe 31L was running shortened that day?  Entry at B10 onto the displaced threshold would also give them an extra 1000ft - V1 just past the aim point and rotate near the end of the TDZ markers seems sensible enough.

EDIT
After running a series of simulations, it seems difficult for the VC-25 to be able to takeoff from where we see it, even when starting from B10. The VC-25 is 525,000lbs empty.  With only 100,000lbs load (fuel+people) it can takeoff by B5 at flaps 20, but only by lifting off below V2 (no wind).  This has to be a landing (confirmed by the newly discovered set of photos), but it is a very late landing indeed.
It also seems that military aircraft of the United States are exempt from the requirement to execute a missed approach in the case that they can't make the landing within the TDZ by DA/DH (using &quot;normal&quot; maneuvers), so perhaps the pilot just didn't care and bobbled it in anyway.  The plane did touch down in the TDZ, but just barely.