Question

what strange things do Mrs. hall notice about the stranger ? how he is different from other customers of Mrs. hall?

Answer 1

Because its habit and behavior and he has never seen him before 

Answer 2

stranger was wrapped up with the bandages and was behaving strangely. he was in bad tempered and always behaved rudely. he was wearing goggles and his coat even after he entered the parlor. 
he is different from other customers as he never spoke to anybody else. he always used to sit in a corner and murmur to himself.