@jasnell Right. But I don't think we have a way to specify the encoding, although I guess one could just use some heuristics and assume base64 unless proven otherwise. Like this:
{
"type": "Image",
"name": "1-pixel GIF",
"mediaType": "image/gif",
"content": "R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7"
}