two girls looking out the window at 'Hair at Hart.'
Two kids wait for their mom to finish her hair appointment.
"Two kids," is a rephrasing of, "two girls." In order for the mom to attend her hair appointment she must be at 'hair at Hart.'
Kids can be girls, so two girls can be referred to as two kids.  The name of the store " Hair at Hart " would imply it is a place to have a hair appointment.
two girls are two kids looking out the window at 'Hair at Hart is that they wait for their mom to finish her hair appointment.