Why was "all" placed there?
Native speaker’s answer
Rebecca
When speaking, "all" is commonly placed after "you" to address more than one person. Ellen is speaking to her audience, which is a large group of people. Thus, she has added "all" to indicate that "you" is plural. Ex: Thank you all for attending this event tonight. (Plural "you") Ex: Thank you for your present. (Singular "you")