What is beauty on the last two pages of the novel?

The last two pages of Zadie Smith's novel On Beauty show Howard utterly fouling up his last chance at tenure. He gets to the lecture hall for his Rembrandt presentation late, and half-way through his introductory speech realizes he left a yellow folder in his car. I assume this folder holds the speech that was supposed to get him tenure. This disrupts what momentum he carried in, having hastened from the house late, sweaty, and with the latest family disaster in mind - a disaster, by the way, that was entirely his fault. (It's bad timing all around).

When he realizes he left that folder in the car, he can't seem to make a split-second save of his lecture. Instead, he starts the power point. By then, he also catches sight of Kiki in the audience - this seems to finish what little concentration he had mustered. He flips through all the paintings his lecture was supposed to cover without saying anything. The last picture is a painting of Rembrandt's love, Hendrickje. Smith describes the quality of the woman's skin in the painting in a way that is beautiful. One line suggests Howard is looking as closely at this painting as his audience is: "He looked out into the audience once more and saw Kiki only." What else would he have been looking at to turn and look at the audience and Kiki for? He had to have been staring at the painting. Kiki is described often in the novel, and her skin is one of the things about her that receives the most attention - apparently, she has beautiful skin. The woman in the painting has beautiful skin as well.

In this moment, he is looking at the painting the way he often looks at Kiki - seeing her as beautiful, and seeing so much of his life reflected in her person. Almost as importantly, he doesn't say anything - he gives the title of the painting, Hendrickje Bathing, and that's it. After a career built on saying a great deal, and all of it having to do with the fallacies in theories of beauty and genius, he manages to look at the painting as a record of something beautiful for the sake of beauty and love.
Hendrickje Bathing by Rembrandt