What
When the new actorId option is set, the request that reads an artifact frame adds &actor=id to its address, which tells the server who is reading.
Why
In practice, artifact reads can now identify who made them.
Something disagreesSomething we can check disagrees with this entry, or the writer said they could not settle it.
The writer flagged doubt
The finding does not say what sets `actorId` or where artifact frames appear to a user.