The purpose of this inspection is to educate the buyer about the "skeleton" / rough framing of the home, what materials have been used, and how they are connected and interact with one another. It's your best opportunity to discover defects / potential problems with roofing, walls, flooring and foundation before the finish materials are installed. It can also help discover related issues with air sealing, plumbing, electrical and mechanical such as missing nail plates, missing fasteners, inadequate nailing, inadequate support and much more. It can also help resolve and calm concerns about things that appear "questionable" to you!
The buyer should follow up with a final inspection just prior to settlement. This inspection will cover all of the major systems and components after the finish materials have been installed. There is also an optional "punch list" to inspect the cosmetic items, because in new construction, there is and should be an expectation of quality, function and a standard of care with reference to paint, carpets, floors, appliances, trim, doors and windows, etc.