Final answer:
The decal that should be displayed on certain vehicles is an equilateral triangle, which serves as a warning for other drivers about potentially slow-moving vehicles. A hearse with a 'LASTRYD' license plate may suggest that the owner has a sense of humor about their profession.
Step-by-step explanation:
The question refers to a type of decal that should be displayed on certain vehicles. This decal is an equilateral triangle, which is a warning sign to other drivers that the vehicle may be slower-moving. Specifically, it is typically required on vehicles such as tractors, farm equipment, or horse-drawn carriages when they are on public roads. This decal is a safety feature designed to increase visibility and alert drivers to the potential need to slow down.
Regarding the given illustration of the hearse with the license plate "LASTRYD," a common perception might be that the owner has a sense of humor regarding the nature of their business, or that they have a more lighthearted approach to the subject of death.