I love how she is imitating the dog rolling on the floor! This is an example of typical play and social skills development. Imitation is very important, without imitation skills kids will have a difficult time learning, and developing their communication and play skills. You should see your baby begin to imitate simple movements (such as clapping) or facial expressions as early as 5 months!
Does your child have good imitation skills? Speak to your pediatrician if you have any concerns whatsoever, they should be able to tell you if your child's imitation skills are on track.