Smilling and laughing baby in a walker with fire engine airplane mobile and other toys on the floor
The baby's diaper is full of feces.
The baby is smilling and laughing baby which indicate that it is comfortable which would not be the case its its diaper is full of feces.
If a baby's diaper is full of feces, the baby is unlikely to be smiling and laughing.
A baby is not usually smiling and laughing when the baby's diaper is full of feces.