It's an American flag, and the following note:
"Hey Mom, what's happening? Here it is, your birthday present. Of course it's a couple of weeks late, but you can understand why - the post office of course, doesn't have same day service, and additionally I wanted to wait until these pictures came back from the printer. So, as the certificates say, the flag was flown over (his camp) on your birthday. There is only one flagpole on each Army post, and for one day this flag flew on (his camp's.) I thought you might get a kick out of it. So, happy belated birthday. Love, Evan.
The pictures are of him standing under the flagpole.
I'll tell you what the certificates say after I've shed a few tears.;^)