Create a mini plant, which exactly repeats the look of a large tree
And no... that too I do not really agree with. You cannot replicate a real tree in miniature. It is an impression of a real tree - not just any tree, but an old, mature tree, that shows it has struggled against the elements and survived.
how about using the phrasing: to create the feeling of a large, aged tree in minature? with the emphasis on the word feeling.
I think bonsai in a unique way expresses parts of life in art, that other artforms cannot. Obviously it is not only art, and not only horticulture, but because a tree is always changing, and growing, etc, it can express the ever changing nature of life that a painting cannot.