I think what she means is for an artist to create it a bit more information is needed, saying you’re not too picky leaves too much room for interpretation, some artists don’t mind having free rein but it’s a lot of work to go through for if you don’t end up liking the finished piece.
Try to add a list of your character’s details to the original post (I recommend this instead of a simple screenshot as some screen resolutions can make determining small things like close skin colours and eye colours, hard to figure out.), Write down what outfit you want the character to wear, not three options, pick your favourite that will best represent the story. Say what pose you want the character to be doing, if it is an episode animation, say which one, if it is a custom animation, provide a good description or a reference picture. Also include things like whether you would like it to be an edited cover (using an episode character picture and then transferring it onto the cover) or a drawn cover, (where an artist draws the character from scratch), Preferably also provide either a background picture (In which case ensure it is either from the episode catalogue or from a copyright free image site, not google) or at least give a good idea of what background you want it to be on.