Need some advice on improvement my vector

Hi there!
Could anybody help me with my hard reject?
Resently I have got the message with “unfortunately we found it isn’t at the quality standard required to move forvard”. And there was advice to visit this forum and ask fellow autors for some feedback.
So, what’s wrong with this vector image? And what can I do to improve quality to fit the required standart?
I will be grateful for any help.

hi i think that this is not bad, i rather like what u have done to be honest, i just tend to believe that this is lacking shadows in a good deal of places so that the illustration looks more realistic. I also tend to believe the the lighter blue zone (the big one right next to the left side of the mouth) is ruining a bit what u have done rather than bringing anything realistic and or aesthetic to the table so that i believe that your item would better off without it …

Thanks for your response.
Do you think if I follow all your recommendation, it would be enough to resubmit this item?
Additionally I want to remove the red sign to make the whole “face” visible.