The photo shoot was a lot of fun for this pic. We all acted out the parts, speaking and acting everything so that the expressions would be realistic. I originally just had the smoke from the Green Goblin's glider in the background but Axel Alonso suggested it should be more obvious what was triggering Peter's spider-sense - hence the Vulture.

Although I like this pic as it stands, I think a word balloon with Peter saying "You see..." and then a connecting thought balloon with "Uh-oh, my spider-sense is tingling!" would really finish the image off.

The concept pencils for this image can be seen here.