There are two Talk bubble clips that share the name "Reads Aloud". One of the them is available for everyone to use, and the other is exclusive to VIP members in the Movie Maker. The duration of the clips changes depending on how much text you add in.
The first Reads Aloud clip (which is available for everyone to use) is used for when you want one of the characters to read something, for example: a book, or a letter.
The second Reads Aloud clip is exclusive to VIP members only, and it is used to make one of the characters read something carefully.