That is value add. People want to know that the salesperson is on their wavelength.
The role of a good salesperson is to understand the customer's problems as best they can, then explain how the product will help resolve them. That is good for everyone - the business and the customer. It is helpful if they show the customer that they are trying to understand their emotional frame.
To make that clearer; imagine the opposite - if the salesperson purposefully adopts different body language that'd make the customer uncomfortable and less likely to buy a product even if it could have been useful and cost-effective for them. Value would be destroyed.
It is a value added if you believe that you are selling a good and useful stuff. Buying the item would add value to the customer, so tricks to convince the scared customer to take the right step is added value.
The role of a good salesperson is to understand the customer's problems as best they can, then explain how the product will help resolve them. That is good for everyone - the business and the customer. It is helpful if they show the customer that they are trying to understand their emotional frame.
To make that clearer; imagine the opposite - if the salesperson purposefully adopts different body language that'd make the customer uncomfortable and less likely to buy a product even if it could have been useful and cost-effective for them. Value would be destroyed.