Liquids only
Put powders through door probably means it`s ok to add liquid additives like bleach or softener through the designated hole as not to mess up the washer as it is in picture # 1.
What I never get is how could a run down place like this have been in business?
Of course those washers were old in 1969 when the movie was made, but for heaven`s sake is it so difficult to use a wet sponge or whatever it takes to clean the exterior of this poor washer?