Dog lie down and growls at owner

My dog Maura is a Great Dane mastiff mix and she is a little brat who talks back to you. She sounds super scary and mean when she talks, but she’s just moody and wants to complain. Definition of all bark and no bite. Her deep voice scares away new friends, but she’s just a little spoiled. She also looks like a doofus. This is my mom on the couch with her, and she just starts giving back talk.