properties.schema

{
  "type":"object",
  "$schema": "http://json-schema.org/draft-04/schema",
  "id": "http://jsonschema.net",
  "$ref": "http://localhost/plugins/content/component/model.schema",
  "properties": {
    "instruction": {
      "type": "string",
      "required": false,
      "default": "",
      "inputType": "Text",
      "validators": [],
      "help": "This is the instruction text",
      "translatable": true
    },
    "_reveal": {
      "type": "object",
      "required": true,
      "title": "Reveal",
      "properties": {
        "_background": {
          "type": "string",
          "required": false,
          "default": "",
          "title": "Background image",
          "inputType": "Asset:image",
          "validators": ["required"],
          "help": ""
        },
        "_foreground": {
          "type": "string",
          "required": false,
          "default": "",
          "title": "Foreground image",
          "inputType": "Asset:image",
          "validators": ["required"],
          "help": ""
        }
      }
    }
  }
}