The key concepts to understand are the effective stack (short stack) and how it determines who wins which portion of chips—and more importantly—who wins the bounty.
In a multi-way all-in pot (where three or more players go all-in), the chips are split into a Main Pot and one or more Side Pots based on the players' starting stack sizes.
The Main Pot is the portion of chips that all active players are eligible to win.
It is always capped by the smallest all-in stack, known as the effective stack.
The player who wins the Main Pot only eliminates the short-stacked player if they have the best hand.
Any chips contributed by players that exceed the Main Pot's effective stack are split off into one or more Side Pots.
A player can only be eliminated (and their bounty awarded) in the pot that contains the last of their chips.
In our example, the chips remaining from Seat 4 and Seat 2 created a Side Pot.
Side Pot Breakdown:
Seat 4's remaining chips after covering Seat 1: 9,910−5,920=3,990
Seat 2 covers Seat 4's all-in: 3,990
Side Pot Total: 3,990+3,990=7,980
Result: The Side Pot is contested only between Seat 4 and Seat 2.
Seat 2 (with 3sAs) made a pair of Threes on the board (Kd5h7h3dQc).
Seat 4 (with 10hJh) only had King-High.
Seat 2 wins the Side Pot, which includes the remaining chips of Seat 4. Seat 2 is awarded the bounty for eliminating Seat 4.
You only win a bounty if you have the best hand in the pot (Main or Side) that contains the opponent's last remaining chips.
In this specific scenario, Seat 1 won the Main Pot but not the bounty because they did not have enough chips to cover the players who were eliminated in the Side Pot. The bounty went to Seat 2 because they had the best hand in the pot that covered the eliminated player's stack.