My understanding was that when it comes to amateur fanartists in fandom that there is a large group of people who flock to Japanese artists (from mediocre to amazing) and ignore the non-Japanese ones. Some have the mentality that because it's Japanese = it's better quality. The secret poster I assume is a decent (who knows?) non-Japanese artist who is tired of people not even looking at their work because they're not Japanese. That's what I gathered.