Without- hopefully, sounding too pretentious, and using a bit of artistic license-
If I were in Wash., DC, today, I would stand to the side of that Marine, facing him, and render a crisp salute to him, even though that would be against military protocol. I would keep this Marine company throughout his honorable posting.
As the uniformed Marine, in representing all branches of service in this act of respect, salutes his brothers and sisters in arms passing by, I would stand in my “civies” symbolically representing the citizens of the U.S. of A., acting as ambassador, in showing reverence and gratitude to the uniformed defenders of our liberties. PRESENT... ARMS!!!
Of course the reality is that I would not be permitted to stand in that road, as it is for this day, hallowed ground, consecrated by the act of Rolling Thunder honoring the sacrifice of our fallen men and women in uniform, and as such, is reserved for the lone sentry and his cortege.
Thanks for clarifying this tradition fr me..........