Since images and other large data chunks aren't generally needed in order to validate the spending of a UTXO, miners don't really have a good incentive to keep it around. But since the transaction containing the image is hashed and put into the Merkle tree, and since the Merkle root is embedded in the block header, anyone who cares about later proving the existence of the data in the chain can just save the Merkle proof for the transaction. Miners aren't required to retain Merkle proofs on spent (or provably unspendable) transactions either, so they will probably just keep the parts of the Merkle tree that include UTXOs. You should look into Merkel trees, section 8 of the whitepaper and try to understand the economic incentives at play for each party involved. Just keep in mind that the only thing a miner needs to care about is verifying that the transactions inside new blocks are valid, nothing much else.
Since images and other large data chunks aren't generally needed in order to validate the spending of a UTXO, miners don't really have a good incentive to keep it around. But since the transaction containing the image is hashed and put into the Merkle tree, and since the Merkle root is embedded in the block header, anyone who cares about later proving the existence of the data in the chain can just save the Merkle proof for the transaction. Miners aren't required to retain Merkle proofs on spent (or provably unspendable) transactions either, so they will probably just keep the parts of the Merkle tree that include UTXOs. You should look into Merkel trees, section 8 of the whitepaper and try to understand the economic incentives at play for each party involved. Just keep in mind that the only thing a miner needs to care about is verifying that the transactions inside new blocks are valid, nothing much else.