Final answer:
Robert Indiana is renowned for his iconic LOVE design, a symbol widely distributed across various mediums like t-shirts and postage stamps, and recognized as a representation of the Pop Art movement.
Step-by-step explanation:
American artist Robert Indiana is best known for his iconic image that spells out the word LOVE. The design features the letters L and O stacked on top of the V and E, with the O tilted to the right. The image has achieved widespread recognition, gracing t-shirts, greeting cards, postage stamps, and becoming a monumental sculptural piece in various locations around the world. Indiana's LOVE design is quintessentially associated with the Pop Art movement, capturing the era's spirit with its bold, simple, and direct visual language.