wrong order of property values (if nested object is present?)

[sknebel]

<div class="h-entry">
<div class="u-foo h-x-bar">
   <a href="dogs.html">DOGS</a>
</div> 
 <img class="u-foo" src="kittens.png">
</div>

results in a property where the second value, "kittens.png", appears first:

  "foo": [
                    "http://example.com/kittens.png",
                    {
                        "type": ["h-x-bar"],
                        "properties": {
                            "name": ["DOGS"],
                            "url": ["http://example.com/dogs.html"]
                        },
                        "value": "http://example.com/dogs.html"
                    }
                ]

http://pin13.net/mf2/?id=20190110170507771

It appears to be related to there being a nested object.