The Case of the Suddenly Appearing Plane

I have seen videos here and there of "flight 175" suddenly popping into view. But I just found (courtesy of "Rob"), the best video yet showing this phenomenon.

Strikingly, the plane coming suddenly into view is fairly clearly not from:
1) an effect of perspective, where the plane is suddenly close enough to see
2) an effect of splicing in plane flying footage suddenly on still footage, as one can see a faint blur before the plane appears
3) the plane emerging from behing clouds or haze.

It is very ODD, as the plane simply POPS into view.

There are only two explanations:
1) this was some sort of stealth plane suddenly turning on UA flight 175 "camouflage" before it approaches Manhattan and strikes the WTC.
2) the footage was faked by having a plane digitally inserted into it.