>>51553619>prettierDepends on which character but as shown with the Zoey pic, the movement where Dawn was at the most important stage in her arc, and where she showed her teeth, she was made to look the prettiest she's ever been and a part of that as showing her teeth, because, as stated by you, it was to show her emotions and powerful emotional moments make characters look as good as they can be.
With Serena, she has been going on a downward slope in regards to her character design with each redesign looking worse than the previous. She peeked with her original design because that one looked the closest to her game design and the rest were just more underwhelming than the last.
>coolerNope, girls that show her teeth while still managing to look pretty are always gonna be cooler than just regular girly girls. It is a staple of anime to include a gap moe character that looks girly and adorable and to have her show that she has some bite to her.
>matureMaturity has nothing to do with appearances it is how one acts and even so it is entirely inconsequential to the convo at hand as Dawn is neither more mature in appearance nor actions to Iris and neither is she more relevant or closer to her dream, and even if you consider Serena wearing a different fit as a sign of maturity, it isn't, or her quoting Ash to Koharu, it super isn't, the same thing about not being any closer to achieving her goals still applies to her, not to mention her negative in actual relevance. (2/2)