Well I’m sure it would be somewhat a matter of opinion, but for me, even though the grass provides some interesting lines, I lose interest in it pretty quickly. The rock actually helps to hold my attention. So maybe it’s my short attention span that’s the problem! 🙂 I guess somehow my mind sees a rock as a stronger subject than grass and so I like the rock being there. So… maybe in reality what you’re saying is true… the rock competes with the grass for attention, BUT… it helps keep me looking at the picture!