A representatuve of an estate would usually be a lawyer, but could also be a family member or anyone with power of attorney. It does make sense because Steve Martin is alive, and has an estate. It is ok that you didn't understand what the word 'estate' entailed, but now you are purposfully being obstinate because…

And writing dissertations in the comments is political activism? Did someone say this was the apex of activism? Is this not an entertainment site?