This one's a bit obscure. I've got a post which is a share of an album from Google Play Music. When you view the post, it's a complicated attachment containing "Listen", "Buy" links and so on. But when you grab the post via the SDK, all you get is a title, an image of the album cover and a link. Basically the SDK attachment doesn't really reflect the post very well. The attachment type is "objectType": "audio".
Now I guess you could say the same thing about Youtube. But this means that somebody using the API needs to be aware of and build a representation of every possible attachment.
Post: https://plus.google.com/106416716945076707395/posts/YhLavWoi9Qy
Post ID: z12vhzkjrue3etjxx04ccnti2wb4ejnxysk0k
Returned:
"attachments": [
{
"objectType": "audio",
"displayName": "Rye Lane Volume One",
"url": "https://play.google.com/music/playpreview?preview=AE9vGKq9bZV1vP2JUhloXCtqm09d63mts1p_kwNro89uJH7V1vXzSLAzZ9GsdU6eOHKF_-IXrP8T5TOdU3l9Q2SP5uRtUzWOxyaiYzFii6fwAVblzgQnxZg%3D",
"image": {
"url": "https://lh6.googleusercontent.com/HTuBpdf2SAvpcUxl5x_oN6mWr0Fld4MpprrMsXrWR0xuMbc8pD6gwf9z1nW9QxC9iNvmibmd",
"type": "image/jpeg"
}
}
]
The main issue with 407 was attachments that were completely missing, but in the comments other people are reporting attachments that are incomplete or unhelpful.