On a Mac, what is the hotkey associated with the image of an arrow pointing right ⇥?

Top (Gray) image is Tab

Bottom (Bold) image is Shift+Tab

Mac Keyboard Shortcuts

As was already stated, it's the Tab key.

You can see all of the glyphs associated with keyboard keys using the Keyboard Viewer tool window.

(Note for PC keyboard users: Help button replaces Insert, Numpad + is split into two normal size keys, and Clear replaces Num Lock.)