0xe985e9c5?0xe985e9c5 is the function selector for isApprovedForAll(address,address). Reads whether an operator is approved. Read-only.
When a transaction's data begins with 0xe985e9c5, it is calling isApprovedForAll. The selector is the first four bytes of the keccak-256 hash of the signature isApprovedForAll(address,address), which is how wallets and explorers work out which function a payload is for.