WOW!
My welds always look like someone threw mud and some of it stuck.
One day I’m going to get off my ass and take a class. Some things/people just need hands on instruction.
OP’s brother is an artist.
I’ve always contended that there are two sets of skills in every field, THE MECHANIC, which is the person who is taught, and practiced and studied. The Mechanic can be very skilled and attain a very high level. My mother is a marvelous pianist, she practices constantly. But without sheet music and practice, she is at a loss.
The other is the NATURAL TALENT, the artist.
Not to say the artist cannot improve with training, but these are the people who hear music in their head, play back a song they heard, instinctively pick up a new skill and master it with little training.
OP’s brother is a natural talent.