There are some truly special (like bespoke) orders that can be produced by H if you are granted this privilege--involves iterating a design with them, must be in keeping with the house's philosophy, which can mean looking back into the history of the house for ideas and elements to include--and they have to approve it before it will get made. It can get as specific as choosing the particular skin that gets used (not sure if this is ever done by the client, but, the person supervising the design process and its execution might be doing it).