Help to identify quality issues

There are obvious rendering errors. But who cares, it's anyhow a monster:

The leg / knee is tilted at a wrong angle and seems disproportionate to the rest of the body.

It's always difficult to comment on illustrated fantasy art with respect to why it was rejected, but it might boil down to composition in these cases. The octopus images are too tightly cropped and I personally disdain the square format.  Their commercial value might also be questioned. There are questioned rendering errors in the tree woman.