minecraft-assets/assets/minecraft/items/spyglass.json

{
  "model": {
    "type": "minecraft:select",
    "cases": [
      {
        "model": {
          "type": "minecraft:model",
          "model": "minecraft:item/spyglass"
        },
        "when": [
          "gui",
          "ground",
          "fixed"
        ]
      }
    ],
    "fallback": {
      "type": "minecraft:model",
      "model": "minecraft:item/spyglass_in_hand"
    },
    "property": "minecraft:display_context"
  }
}