Dorian makes it clear when he explains his infatuation with Sibyl Vane that what attracts him to her is her changeability and her artistic skill. In a book that discusses so much the relationship between art and reality, it is made clear that it is Sibyl's art as an actress that makes her attractive to Dorian. Bearing in mind this theme in the novel concerning art and reality, it is highly significant what Sibyl says to Dorian in Chapter Seven to explain her terrible performance:
"The painted scenes were my world. I knew nothing but shadows, and I thought them real. You came--oh, my beautiful love!--and you freed my soul from prison. You taught me what reality really is. Tonight, for the first time in my life, I saw through the hollowness, the sham, the silliness of the empty pageant in which I had always played... You had brought me something higher, something of which all art is but a reflection. You had made me understand what love really is."
Thus we can see that Sibyl, through her relationship with Dorian, has realised the limitations of art and has committed herself to reality. However, tragically, Dorian, thanks to his portrait, is a work of art, with his reality being reflected on the portrait. Thus it is impossible for art and reality to be wed together, and he cruelly and harshly ends the relationship. Of course Sibyl, now that she has experienced reality, can never return back to art, and thus kills herself.