My husband's eyes had a twinkle like "St. Nick." (Santa Claus)
I have noticed when I am feeling especially blessed or some semblance of happiness, his eyes look happy also. I do think he is happiest when I am.
I don't think I really noticed if his pictures "twinkled" when he was alive. Of course when you have the real thing in front of you, you don't spend as much time contemplating pictures.
Thank you Cath!