Hi nostr:npub17lmqmq680446scdgvv58snglr3h2phe00thqfe0twa3l8q5mzmusj6c60g,
Thank you for trying out Coop. In the current version, sending a picture works the same as putting a URL in a message and sending it. NIP-17 has instructions for sending encrypted file event messages (https://github.com/nostr-protocol/nips/blob/master/17.md#file-message-kind), but Coop doesn't support it yet. I already have it planned, but I want to wait until Coop is a bit more stable.