That transaction appears to have an image attached: https://www.blockchain.com/explorer/transactions/btc/2fc565c... (see Ordinals Inscription)

The amount of the fee is kind of up to the sender. If the fee is not high enough, miners will not include the transaction in the blocks. But there's no upper limit on how high the sender can set the fee.

Edit: Since a block has a limited amount of space for transactions, transactions with more bytes have to pay a larger fee to get picked up by miners. This one looks really large.

When you make a transaction on the Bitcoin network (and really every other cryptocurrency), you tack on a fee to the amount of coin you want to send. Miners prioritize higher fee transactions when deciding which transactions to include in the next block. Therefore, to guarantee your inclusion in the next block, you would choose to increase the fee you pay.

So, for this transaction, they chose to pay a $5000 fee to guarantee their placement in this block.

This was a historic event people paid to be a part of.

Only 4MB of data can fit in a block. To get priority for your transaction you pay more.

New protocol launch coincided with this block - in chasing becoming the first use of the protocol, users spent thousands to use it or create an asset via the protocol.