@talk72000,
You are unthinking on this. The fellow may not be stalking but he also may be. I don't care if you think it is overblown.
I've been stared at in a library, rather long ago now, and I had a wave of thinking it was creepy at first. The same professor sat kitty corner from me, usually after I was already in the library, and when I looked up from time to time (that's where I used to somewhat rewrite and at the same time process lecture notes) he would often be looking at me. Or, maybe the clock behind me, or the library main desk past our table. Often it seemed
at me, but also not really. I could tell he was busy thinking, and just looking up, sort of like how one drives a car on a non busy road, both thinking and only somewhat attending the road. He was a fairly famous scientist, clearly an active thinker, and I became more comfortable.
A woman tends to know when eyes are boring in at her. It's a different thing, in my opinion.
In any case, I take it as thoughtless that someone would remind her she looks like some actress when she is actually worried re her own observations. You didn't see his eyes.