Complex sentence: Huxley has attributed Warhol's preoccupation with celebrity portraits in part to his religious upbringing; as a child Warhol attended a local Catholic church which featured an iconostasis, a screen situated in front of the altar featuring large-scale depictions of the faces of the Saints.
Split into simpler sentences: Huxley has attributed Warhol's preoccupation with celebrity portraits in part to his religious upbringing. As a child Warhol attended a local Catholic church which featured an iconostasis, a screen situated in front of the altar featuring large-scale depictions of the faces of the Saints.