Final answer:
Rodrigo's mental image of snow is an iconic representation because it resembles the sensory perception of snow, while the word 'snowfall' in his letter is a symbolic representation as it uses language to convey meaning.
Step-by-step explanation:
Rodrigo picturing the snow in his mind is an example of an iconic representation. In Rodrigo's letter, the word "snowfall" is a symbolic representation. Iconic representations are those that resemble the sensory perceptions of the thing they represent, similar to visual imagery. On the other hand, symbolic representations are arbitrary and do not have resemblance to the physical form of the object or experience they represent; they are based on language or other symbols that convey meaning through convention.