The term grooming is often used to describe the manual adjustments made to coffee grounds in the basket after the beans have went through the grinder, and before being inserted into the group head.
The concept of coffee grooming comes from the logic that spreading the grounds evenly in the basket would aid a more even flow of water, and result in a more even espresso.
The argument against this is that once the extract is collected in the demitasse, they blend together and become even. So grooming is more of an act to make baristas look like they really care about the coffee.