A single sensory respect can be associated with any of the five external senses. Sensory does not mean visual only.
Sight: red grapes and a red flower — redness.
Hearing: two quiet voices — softness of sound.
Smell: a rose and perfume — pleasant fragrance.
Taste: honey and sweet fruit — sweetness.
Touch: silk and smooth cloth — softness.
Each selects one quality. A comparison simultaneously in colour, fragrance and flavour instead has three distinct sensory respects, even though all are perceived by external senses.