It was cake. It was for-real (well, no it wasn't for-real, but it was good enough) delicious cake that was not a lie (in the sense that GLaDOS' cakes were lies), and she spent a few long moments just staring at the slice, as if she didn't know what to do with it.

She knew what to do with it, of course, and pulled up a chair, taking a fork and slowly, very slowly, bringing a piece to her lips.

Have you ever seen someone eat cake with pure, unadulterated reverence? Now you have.