That's an incredible shot.
So we're looking at a glow at the western horizon from a pre eastern sunrise? Meaning you can't actually see the sun rising to the east due to it still being bellow the curvature of the earth, or in the case of from San Diego, the Laguna Mts being the horizon? Interesting.
What are you suggesting is the cause of this glow,this lighting phenomena, or are you asking? The question is quite intriguing.
That image was 1 minute before astronomical sunrise. Camera height on antenna mast is around 2000' MSL. The Cuyamaca range to the east (just west of the Lagunas) create the artificial elevated horizon that delays sunrise a little for the basin of San Diego. So, yes, San Diego (and the Woodson peak) were still in shadow, minutes before the sun would rise over the Cuyamacas.
To the west, a surface layer haze, trapped by a temperature inversion, extends up to around 1000' anywhere from 10 to 25 miles off shore. This is what is catching the rising sun's first rays while land and coast to the east are still in shadow.
The peninsular mountain ranges east of San Diego could be the source of shadow and why low elevation haze to the west is glowing while elevations closer but lower to the Cuyamacas are still in twilight. However, there are no mountains to the west and yet the same anti-solar glow sometimes occurs to the east at sunset.
My conclusion is it's a feature of a globe earth, but I offer it up for discussion.
(I'll see if I can find a comparable eastern glow during sunset photo.)