Here is an code example:
shh.post({
"from": myIdentity,
"topic": [ web3.fromAscii(appName) ],
"payload": [ web3.fromAscii(myName), web3.fromAscii("What is your name?") ],
"ttl": 100,
"priority": 1000
});
What stops us from putting files in the payload i.e., large base64 encoded or hexadecimal string?