What does the mixer brush do that other brushes don't?

After first arriving in new york, charlie parker took a job as a dishwasher at jimmy's chicken shack, where played the piano nightly. listening to his astonishing harmonic restructuring, virtuoso phrasing, and breakneck tempos every night for three months, charlie parker challenged himself to adopt these qualities into his playing, and he continued to practice tirelessly.

Where is the photoshop flaw in this picture? a. the fish is too large, b. the head has been pasted on another persons body,c. the guy has no hands, d. the background has been altered.

The way people view and understand an object or subject depends primarily on what ?