No two breeders will have the exact same answers, but Show quality breeders will give similar answers.
In shows, dogs are judged against a written standard that describes the ideal specimen of that breed. Standards describe proportions, balance, required markings, size, expression., and in the Boston Terrier case the head, which best enables the dog to perform. Cosmetic requirements, such as coat color and desired markings, are also part of most standards.
Theoretically, ‘pet’ quality refers to dogs who vary from the standard of the breed in such a way that it, in the breeder's opinion, would be difficult for that dog to finish its championship. ‘Pet’ quality does not, and should not, refer to structural, health, or temperament problems that would impact the dog’s quality of life.
Many standards contain words such as ‘elegant’ that leave room for interpretation. And as in so many things, no two people will agree on the interpretation of ‘elegant,’ so what one breeder considers a show quality dog, another would consider a pet.
Responsible breeders, who show dogs , are knowledgeable about as well as able to identify by sight their breed standards. They perform applicable health checks and certifications on their breeding dogs, socialize and evaluate their puppies, and stand by the dogs they sell. Dogs are chosen for breeding based on their genetic compatibility, not because “I have a female Boston and you have a male Boston so let's..."
Responsible breeders will be there as a resource to the new owners, supplying information and general guidance if it is needed. They will be concerned about the welfare of that dog for the rest of its life, so they will want to be sure it’s the right home for that dog. A Responsible breeder will not sell to brokers or puppymills. Good breeders ask potential buyers lots of questions, and may even require references. They will be able to provide you with references as well.