The caption for that picture in the link says the Lip is at the upper right corner of the picture. I'm inclined to think that the snowfield in that corner of the picture is the top of what's called the Sluice. The Lip would be to the left, perhaps midway across the picture. I found this diagram:
http://timefortuckerman.com/routes.html
although it may be just a matter of camera angle and zoom being different. The small shadow area at the bottom of the picture suggests the shot was taken from below the top of Boott Spur, on the south edge of the ravine. Still, the Lip is sort of just below where the slope coming off the summit cone bottoms out near Tuckerman Junction and heads upward gently toward Boott Spur. That would make the rocks at the top of the left edge of the picture the Icefall.