What does the general document barcode paragraph polygon represent? (2023-07-31 GA)

Question

I have been reviewing analysis results for a pdf file which has a code39 barcode at the top of the first page. I have analyzed the document using the general document model with the barcodes feature in the 2023-07-31 GA API version. The barcode data returned makes sense, but I am unable to make sense of the paragraph polygon which represents the barcode.

The paragraph data is as follows...

      {
        "spans": [
          {
            "offset": 0,
            "length": 9
          }
        ],
        "boundingRegions": [
          {
            "pageNumber": 1,
            "polygon": [
              0.0023,
              0.0011,
              0.0322,
              0.0011,
              0.0322,
              0.0024,
              0.0023,
              0.0024
            ]
          }
        ],
        "content": ":barcode:"
      }

I'm struggling to understand what the polygon represents. It isn't the polygon of the barcode because it doesn't match that returned with the barcode information. It isn't the polygon of ":barcode:" because that text is just a placeholder in the "content". Can someone explain what this polygon represents?

For reference the data for the barcode is...

          {
            "kind": "Code39",
            "value": "XXX-914458-10282022-0000001",
            "span": {
              "offset": 0,
              "length": 9
            },
            "polygon": [
              0.4728,
              0.2292,
              6.7522,
              0.2292,
              6.7522,
              0.4965,
              0.4728,
              0.4965
            ],
            "confidence": 1
          }