I like the composition and you nicely captured the harsh shadows on a sunny afternoon.
In other words, I looked through the piece closely and found 39 single pixels. :P
The greens you've chosen for this are beautiful and the lighting looks wonderful, especially on the tree trunk.
The study went really well! The light feels natural. Well, I'm gonna find the single pixel
Edit: Found 2
Nice, inspired. Kinda wish there was some kinda dappled picnic happening there, light cascading all over the shapes (i guess its practice as you say)
@Flinigan, including diagonals or not? :)
@TofuPxl, it is a gorgeous piece of art. My favourite thing is that distant hills are already teal, but not pale.