Brothers are separated. The big one is on the left and the small one is on the right, because of the overall situation. In the composition, so the older brother will play below, and the younger one will play below. So it is very correct to say that the big one is on the left and the small one is on the right.
There are many things that we pay attention to in our daily life. The only thing we know about this kind of thing is. Just do what you know. If you don't know, you really have to ask. An expert who knows, an expert who knows, he must have a story to tell. So don't do anything casually.