Built-in copy protection

If a sufficiently skilled player doesn't want other people to copy his trick, he can design it in such a way that merely seeing a perhaps-not-the-greatest-quality video of it may not communicate quite enough information to learn the trick. This is generally accomplished using subtle but important formations or movements, almost-standard-but-not elements, carefully *concealed string maneuvers, high difficulty, or something along those lines.

Of course, the presence of those elements does not necessarily mean that it was intentional. There are plenty of players who simply enjoy exploring those frontiers, and the idea that their tricks are hard to copy may not be a significant consideration, if at all.

Notable occurrences: magic drop, Aqueous