I think the foreground of the image is fantastic, strong vibrant colors and excellent lighting on the rider and griffin. I can see the light striking the feathers and bleeding through to the arm. However I find there to be a clash with the background and the foreground. There is heavy shadowing on the underside of the griffin and heavy shadowing on top of the tree leaving a strip of brightly colored region in the lower half of the image which then darkens to an ambient light/shadow area. Plainly it feels unbalanced.
I think adding some more bounced light to the under (furry) body of the griffin will balance it a bit better as well as adding some lighter colors to the tops of the clouds it is flying through (thus facilitating the bouncing light more). I'd probably add a bit of bounced light to the closest seagulls as well (VERY LITTLE). My reasoning for this is considering the elf/rider has a considerable amount of light beaming down upon them from behind, presumably from the sun, I think there should be a bit more light bounding off the clouds the griffin is flying through, this is also supported by your rim light around the lower arms.