A random emoji row for a bio, a caption or a game of consequences, drawn from a set chosen to render on every major platform.
Unicode defines well over three thousand emoji and drawing uniformly from all of them produces a bad result. Most are rarely used, many are recent additions that older devices render as an empty box, and a large share are skin-tone or gender variants of the same base character, so a random draw returns near-duplicates. The set here is a smaller hand-picked spread across faces, nature, food, objects and symbols, chosen from characters that have been in the standard long enough to render on essentially every device in use.
Picking one for a bio or a caption is the obvious case, and it works because the constraint is what helps, being handed one at random is faster than scrolling a picker for two minutes. Beyond that, a random emoji makes a decent daily prompt for drawing or writing, a fair tie-breaker, and a way of assigning symbols to people in a group without anyone choosing. The no-repeats toggle is on by default because a list with the same emoji three times is almost never what you wanted.
Because most are rare, many are recent enough to render as an empty box on older devices, and a large share are variants that make a random draw repetitive.
In practice yes. The set is limited to emoji that have been in the standard long enough to be supported across current iOS, Android and Windows.
Not with the no-repeats toggle on, which is the default. Switch it off if you want independent draws that can repeat.