The phrase "observant eye" means having a keen and attentive perception or awareness of things happening around you. It refers to someone who pays close attention to details and is quick to notice and understand what is going on. Full definition
Crialese, himself an Italian emigre, displays a wonderfully observant eye and deft touch for comedy and dialogue. (filmscouts.com)
«After the main plotline of the abduction takes over, Everybody Knows becomes a very different movie with Farhadi's trademark observant eye and passion for uncovering the human condition stamped all over it. (awardsdaily.com)
Jason Andrew, the curator of this exhibition of female artists that spans a century and focuses significantly — but not exclusively — on abstract painting and sculpture, has one of the most observant eyes in art. (nortemaar.org)