I was in the neighborhood today. The tower facade looks like the low-rise, but with a couple of curves. And you can see the start of the angle that will become the "gash."
S Van Ness side
1580 mission 1 by
botoxic, on Flickr
Corner of S Van Ness and Mission
1580 mission 2 by
botoxic, on Flickr
Mission side
1580 mission 3 by
botoxic, on Flickr
Further up Mission
1580 mission 4 by
botoxic, on Flickr