How can you tell if its very skilled or not? You aren't an artist, your mother is. Thats like me saying my father is a pro basketball player and therefore I know everything about being a skilled basketball player.
That logic is a bit flawed.
I have drawings of fish that vary greatly from that so does that mean that its bad? NO. Art isn't all supposed to be the same, thats the beauty. Each artist has their own style. If all art was the same then it wouldn't be art.