To me, the most obvious tecnical issues are that nothing in the picture is sharp and there is banding in the dark areas.
Hope that helps,
Michael Niessen - Photographer, photo-editor, educator
I'm sorry to say this, but this is pretty bad compositing. The lion is badly cut out and the lighting is not right. It also looks like it's overly blurred or out of focus.
In addition to the previous valid comments, you should be aware that Adobe Stock does not accept black and white conversions.