In the episode 5, the Mandalorian communicates with two Tusken Raiders using sign language.
In the Star Wars universe, what sign language is he using? Is it a special sign language to Tusken Raiders, or a language commonly used on Tatooine, and in such case how did he know it?
Maybe there is a common sign language for communicating with droids or other Star Wars races that cannot speak?
Or perhaps is he improvising?