Other mistake: When Blanche gets her citrus plate in the mail, she receives it in a box. She takes it from the mailman and it shows a normally taped up package, yet she just lifts open the flaps like they aren't even sealed.
Continuity mistake: At Big Daddy's (Blanche's father) funeral/passing, Blanche shows Dorothy around her childhood home but it was revealed in season 1 episode 24 that Big Daddy had sold the property to pay for a music tour and to escape the constant reminder of his late wife, the house was named Twin oaks.
Answer: Ice makers were a new invention, advertisement purposes.