"The Birthmark" has lots to say on human nature, but its most important assertion is that to be human is necessarily to be flawed. To strive for perfection is to deny one's own mortality, to deny what makes us human, and to achieve such perfection is essentially impossible. The story also examines the division between man's physical, earthly half and his lofty, spiritual half. "The Birthmark" seems to argue that part of us is necessarily earthbound, yet part of us will always seek to be immortal and spiritual.
Aylmer loves the idea of Georgiana, not Georgiana herself.
Aylmer genuinely loves Georgiana.