I didn't have time when I posted this yesterday but I'll add some further details. Essentially this is an axolotl at someones workplace and when I told them that it was underweight they were quite adamant that it was not, and I was concerned that I was just misled by the angle or something. Sometimes I honestly find it difficult to tell when people post images on this website. If people agree with me that he is too skinny then I will persevere in telling him to do something about it.