Answer:
Such illustration could be considered, a prototype.
Explanation:
The above illustration is considered to be a prototype because the prototype theory suggests an ideal way of presenting a small concept that can be used as a reference to the complete image of what is being represented with all the expected features and qualities.
Marvin's description of the sailboat to Regor is an example of the above illustration, reason being that Marvin would describe in details the color, height, width, the materials, etc of the sailboat to Regor through the prototype they have.