Rejected Quality Standards Required

Hello friends,
I have a character mascot design that I uploaded earlier, but I received news of rejection of this design with a notification “We found it isn’t at the quality standard required to move forward, and you won’t be able to re-submit this items again”.
I don’t know where the error is?!! I need help you so I can improve my design.

And here is a preview of the rejected design:

hi hard to tell u what is the real problem for this item, as I do not consider myself as proficient enough in this field , however , as a designer, here is what I think. I believe that the illustrations are lacking relief indeed and that there should be some shadowing to prevent your drawing from being flatter than expected if u ask me. I think that this should materialize a bit everywhere like on body parts, clothes, hair and so on and even sometimes to objects as well so that all goes more lively, looks more outstanding and lively. Apart from this, I believe that eyes colors are really not a great choice as they fail to stand out and also tend to flatten the general relief a bit more, in the process, too. Think that the global style is a little outdated if u ask me and that has to have an impact on commercial attractivity of the item , in my opinion … I also assume that maybe there could have been a better way to “scenerize your characters” in the preview file, like , for instance , doing lookalike manga vignettes or comic book environment. Do not get me wrong, what u have is cute but as think it would take a bit more work on illustrations and on the global style. I would personally recommend to the works of my friend @memoangeles who is having great illustrations and who is a successful author here, maybe to inspire u about modern illustration styles …