It is a bug? All image's linkForm is "EmbedByReference" in a pdf file's xmp

It is a bug?

All image's linkForm is "EmbedByReference" in a pdf file's xmp.

but the image is linking ,is not embed.

<xmpMM:Manifest>

            <rdf:Seq>

              <rdf:li rdf:parseType="Resource">

                  <stMfs:linkForm>EmbedByReference</stMfs:linkForm>

                  <stMfs:reference rdf:parseType="Resource">

                    <stRef:filePath>C:\Users\Public\Pictures\Sample Pictures\Tulips.jpg</stRef:filePath>

                  </stMfs:reference>

              </rdf:li>

              <rdf:li rdf:parseType="Resource">

                  <stMfs:linkForm>EmbedByReference</stMfs:linkForm>

                  <stMfs:reference rdf:parseType="Resource">

                    <stRef:filePath>C:\Users\Public\Pictures\Sample Pictures\Penguins.jpg</stRef:filePath>

                  </stMfs:reference>

              </rdf:li>

            </rdf:Seq>

        </xmpMM:Manifest>