I believe your first proposition is likely to be the case, Mr, Barr. If you enlarge the picture, you can clearly see slightly thicker, albeit lazier, smoke coming from 497's stack, as if she were indeed being pushed by 496. And it would be
very unlikely that anyone wishing to keep his job would walk away from two
live locomotives with their radius rods set for motion of any kind!
However, we don't know the year of the photo, so if Roosso
was around at that time, your second proposition could also be true...