I only remember seeing somewhat distant peaks from the road to Ollantaytambo. They were not close enough to get a clear photo as in the OP, so I guess that the photo is taken closer to the trailhead. I didn't hike the Inca trail, but took the train from Ollantaytambo. And I do remember seeing towering glaciated peaks from the train. The train didn't go fast, but the Rio Urubamba canyon is pretty steep, and by the time I had my camera ready, it was hidden again, so, unfortunately, I have no photos.
Looking at the map, there really is just one candidate: my money is on Nevado Veronica (location -13.165,-72.326). I checked with Google Earth, and while you can't see it from Ollantaytambo, the valley opens up nicely a little bit further to the NW and it's in view - provided there are no trees or other obstructions of course. So, that's where I guess the photo could have been taken.
Here is a pic I found with a peak that looks very much like the one in the OP:
It's on this site, and the author labeled it Nevado Veronica.