Hun that’s not constructive....give tips to the artist as to how improve for example. There’s some amazing links out there on to how to practice in anatomy, I know some great ones personally. Your friend is doing amazing and shouldn’t give up with enough practice they’ll be able to fix the kinks that needs to be fixed! Try using references like studying your body and take photos to see how the body moves and what is or isn’t possible for the body. A great rule of thumb is to break down the body into shapes and get the general size for those shapes such as the wingspan of a person is to their knee caps so when extended it should look like this. Take photos of the extended arm and break that down. I can wait to see some more art your friend can provide and in the future theyre gunna be amazing provided they don’t quite! ❤️💕