The mystery person in today's Laurel and Hardy photo has been identified! His name is (or more likely, was) Fernando G. Toledo. a writer for the Spanish movie magazine, Film Selectos. He was visiting the set when Stan and Ollie filmed the Spanish language version of their feature film, Pack Up Your Troubles and he wrote an article about it. The I.D. was sent to me by Myles Lobdell, who found it on a forum where it was figured out by Laurel and Hardy experts Dick Bann and Piet Lindner.
As you may know, the early Laurel and Hardy sound films weren't dubbed for foreign markets. They actually filmed each movie several times — once in French, once in Italian, once in Spanish, etc. — bringing in actors who spoke the language in question for each version. Stan and Oliver read their dialogue from an off-camera blackboard that showed phonetic translations. That's what they were working on when that picture was taken.
By the way: I'm going to continue posting photos of Laurel and Hardy but after we pass #300, they'll become a once or twice a week feature and they'll be bigger. I may also repost some old ones in larger versions. For some reason, I really like it when I can look at my blog and see Stan and Ollie looking back.