Iris Cohen schreef
I wrote: A bonsai is a living and evolving work of art. It may be
kept approximately the same size for years. The grower may choose a
different front, may let it grow larger, or may cut it back & make it
smaller, then repot it in a different pot, just as a curator may sometimes
put a painting in a different frame.

You wrote: Whenever the owner of a work of art wants to change
something about it, for example to fit it into a frame or close spot, he is
likely to get sued by the artist, who regards this as defamation of the work
and an infringement of copyright.

This question is discussed in bonsai circles all the time. In general,
when you buy an ordinary commercial bonsai, especially an anonymous one, it
is now yours, and you are free to restyle it as you please. In the case of a
very old masterpiece bonsai, the current owner usually tries to maintain the
original style as intended by the original artist. But since a tree is
alive, there are problems. Sometimes a major branch dies, or a couple of
trees in a group die.
Sometimes the proportions change as the tree ages, even if the overall size
is kept the same. In these cases, a big expert is called in for a complete
makeover, which is often published in a magazine. One interesting situation
is the Lars Anderson bonsai collection at the Arnold Arboretum. They were
brought to this country by the embassador to Japan around 1905, and were
created in the bonsai styles of that time. Let me tell you, I have seen
them, and by today's standards, they are BORING. But as the earliest
examples of bonsai in this country, they have great significance. The
arboretum people have maintained them in their original styles as much as
possible, but in some cases, they had to completely restyle them for the
health of the tree.

+ + +
You are saying now that only very old masterpiece bonsai are comparable to
works of art, or perhaps not even that but comparable to historic monuments?

Ordinary bonsai are just there to feel sorry for (oh yes, their misery is
boring ...).
PvR