As mentioned before, the setting sun at the end of the day can make some things hard, and soften others. In this case, the sharp edge of shadows harden the thorns which protect the new growth and the stones themselves seemed plintered by the shadows.
The elements for Iron Photographer 20:
1 - one to five stones
2 - something green
3 - sunlight
I don't think anybody will need to have the first element, one to five stones, defined. I hope the second element, something green, is equally self-explanatory. The final element, sunlight is the simplest of all.
The only question I can anticipate for IP20 is whether or not one (or more) of the stones can also be the green element. The answer to that is sure, why not?