Something about this pic doesn't sit right with me. I watched every single Apollo launch, but I always recalled the launch vehicles being pretty much vertical as they ascended until they were much higher. I don't know how high the flag was in this picture, but I can't imagine the Saturn beginning its program at the altitude that seems to be indicated. This was either taken with an incredibly long lens (not entirely unlikely, given the hazy appearance of the Saturn V and its angle), or a very inspired mash-up.
I would love to be proven wrong, because I like the shot.
"A condensation cloud forms around an interstage as the Apollo 11 Saturn V encounters max Q, at about 1 minute 20 seconds into the flight (altitude 12.5 km, 4 km downrange, velocity 440 m/s)."
As the Saturn is probably about 15km from the flag (slant range plus the distance from the pad to the flag), I don't see how it can be that big relative to the flag.
I do know there are some techniques to do photos like this, but I am not a photographer.
Regardless, the picture is posted to several NASA web sites, so it was probably done by a NASA photographer.
“I would love to be proven wrong, because I like the shot.”
It is quite lovely, and you are right, quite fake. That angle of attack as seen behind the flag would only happen if it were crashing into the ocean, as that rocket is approximately 450 feet tall, and doesn’t have the structural integrity to hold together in the lower atmosphere, and high speed. Also, note the cloud around the middle, where the aerodynamics buffet with breaking the sound barrier.
However, this is the poor description of a layman in aerodynamics (me), and we really need an aeronautical engineer to explain it. I have analyzed many videos and photos of the shuttle and its shock waves, particularly the challenger and colombia. Explore further, you will be intrigued.