A female child in a white, long-sleeved shirt is kneeling on a couch, laughing as her hair is sticking up.
A child yells angrily at her mother.
The child can not yell angrily if she is laughing in sentence one
A child laughs in the first sentence then in second the child yells angrily and is not the same at all.
A child cannot be laughing and yelling angrily simultaneously.