Only a tiny patch of your shirt is visible and you’re wearing bright, contrasting colors.
It is a matter of lighting and resulting shadows. When the referenced photo was taken, I didn’t yet have the lighting set up to simulate the actual lighting at 12:30 pm on 11/22/63 in Dealey Plaza. And, when the photo website I use becomes useable again, I will post some photos that demonstrate revised lighting to show that the angle of the sun at 12:30 pm on 11/22.63 reduces those shadows. Plus a thinner arm without a loose fitting shirt sleeve would reduce the shadows further.
Brennan somehow thought he saw this person from the belt up at the time of the shot. I don’t see how that is remotely possible, so what else did he imagine/embellish?
Mr. BELIN. At the time you saw this man on the sixth floor, how much of the man could you see?
Mr. BRENNAN. Well, I could see at one time he came to the window and he sat sideways on the window sill. That was previous to President Kennedy getting there. And I could see practically his whole body, from his hips up. But at the time that he was firing the gun, a possibility from his belt up.
I will show you, with photographic evidence, that it is possible. Unfortunately we have to wait until the photo sharing website is useable again. I think Brennan is “guesstimating” (because he must not have remembered exactly how much of the man he could see) when he says “a possibility.” But it appears to me (from my experiments) that Brennan saw almost down to the belt, but not quite.
Okay, it appears that the photo sharing website is back up again. So, here is a photo showing the new light source located to simulate the position of the sun at 12:30 pm on 11/22/63. According to the US Naval Observatory website this would be at an altitude of 37-degrees and an azimuth of 184.9-degrees. I used a laser level and accounted for the orientation of the TSBD at 15-degrees counterclockwise from due north.
Here is a photo, from Brennan’s simulated angle, using the new (simulated sun position) light source. This depicts the sniper looking towards the Main & Houston Streets intersection. The t-shirt is light colored to go along with the description by Brennan.
And here is a photo showing the firing position. Note that the shadows cast on the light colored shirt are discernible but the portion of the shirt that is in the shadows is still visible.
For those who might declare that LHO didn’t own a light colored shirt, please see CE 520 in the lower part of the photo below. It is a dingy white t-shirt, versus the bright white, that we identify with the dress shirts worn by men with their coats & ties. So, I think this might account for Brennan’s description of “possible khaki” colored.