In context, from p. 67 as cited above:
Wyeth ultimately came to believe that his urge to create an art that could somehow articulate the dualities and paradoxes of his experience was constrained by his portrait practice concluding that, “Most of my portraits would have been better if had removed the figures.” [footnote 85 citing Meryman Archive] Interiors and exteriors without figures and mediated by windows alone proved to be a more effective vehicle for expressing the strange admixture of realism and abstraction, presence and detachment, connection and disconnection, intimacy and alienation that Wyeth sought.