Why would an Order resource be missing amount fields?

What does it mean when an Order resource has no amounts (e.g. total_money ). For example:

{
  "id": "8O9WeWSbPjlw1yeV",
  "location_id": "3GPC8TJJ7FHE3",
  "created_at": "2020-03-07T18:36:28.000Z",
  "updated_at": "2020-03-07T18:36:28.000Z",
  "state": "OPEN",
  "tenders": [
    {
      "id": "NKiSJSFYgHfOeQYWT6DjfluaB",
      "location_id": "3GPC8TJJHE3",
      "transaction_id": "8O9WeWSbPjlC9SL6uTw1yeV",
      "created_at": "2020-03-07T18:36:28Z",
      "amount_money": {
        "amount": 16500,
        "currency": "USD"
      },
      "type": "CARD",
      "card_details": {
        "status": "CAPTURED",
        "card": {
          "card_brand": "VISA",
          "last_4": "2893"
        },
        "entry_method": "KEYED"
      },
      "tip_money": {
        "amount": 0,
        "currency": "USD"
      }
    }
  ]
}

Does it mean it’s an empty order?

This seems to be a partial payment. These are currently created through Square’s Invoices product, allowing payments/tenders before the sale is complete. Once complete, it will have all the amount info and itemization present.