Palom is pretty straightforward! He always dresses in the clothes in his icons; they are what pass as mage robes in his world. He makes no attempt at hiding what he is: a bratty little kid with generally good intentions. His default expression is a smirk and his default attitude is insolent.

Most people will also notice that Palom gets more and more rude when he gets annoyed. This is pretty normal. Maybe fewer people will realize that Palom also becomes rude when he feels sad; he usually defaults to anger, instead. It's not really that he's trying to hide it more than it's just that the only way he knows how to cope is to be angry and rude. Again, pretty normal for a little kid.

From his appearance, Palom is very obviously young; however, probably very few people will realize that he is actually only five years old because his speech and his behavior could certainly pass for a ten-year-old's. He is something of a child genius.

And of course, he does magic. Sherlock has no gauge on magic, but he is an exceptionally powerful magician, even compared to full-grown adults.