Complex sentence: 's painting of the "Adoration of the Magi" has an inserted self-portrait at the far right: the position in the corner and the gaze out to the viewer are very typical of such self-portraits.
Split into simpler sentences: 's painting of the "Adoration of the Magi" has an "inserted self-portrait". The position in the (right) corner, and the gaze out to the viewer, are very typical of such self-portraits.