Commentary Par III 109

This is the first time the word 'splendor' (splendore) is used to describe the appearance of a soul in Paradiso (but see also at least [Par V 103]; [Par IX 13]; [Par XI 39]; [Par XIV 95]; [Par XXI 32]; [Par XXIII 82]; [Par XXV 106]; [Par XXIX 138]).  In the heaven of the Sun we learn that the souls are enclosed in their own light (e.g., [Par XIII 48]), thus explaining why we would not be able to recognize them even had we previously known them -- as well as why Dante can recognize the features of Piccarda, i.e., she still possesses features, if they are but faint.  Thus for Constance to be treated in this way, as though she were appearing in a higher heaven, tells us a good deal about Dante's admiration for her.