There was a point a year or more ago where Google Photos had a neat indicator on top of each media item that showed whether or not it was backed up. Thanks to it, you could always tell at a glance which photo or video had been uploaded and which ones were still pending. That indicator disappeared completely, but the Photos team has finally realized the extent of its mistake by removing it, so it's bringing the functionality back.
An upcoming gallery view in Photos should let you see which media items haven't been backed up, and manually choose the ones you want to upload. That's all we really wanted, isn't it? It's a necessary feature for users who don't have automatic backup enabled and can never tell what's uploaded and what isn't, or those who get stuck with a mysterious "30 items uploading" for days on end with no clue as to which item is stalling the process.
The option isn't live yet — at least we weren't able to trigger it in any way on our devices — but the Photos team did update the Play Store changelog to mention it. This isn't the first time the Photos team has put up a changelog before a feature's rollout though; it recently happened with the suggested document crop that doesn't seem to be live yet, and many times before that. One could suspect the team may be trying to steal the thunder from our teardowns by announcing things before releasing them - ha!
If you spot this new gallery view, please let us know. We'll keep our eyes open and update this post with an APK if a new version of Photos is needed to trigger the feature.
Reader binaya bajracharya has this special gallery view already. As you can see in the screenshot below, it's a standalone page that only shows the non-backed up photos (like the changelog explained). You can select any photos and upload them right away. This is different from the cloud indicator we had a couple of years ago and that's still there on iOS, as it's separate from your main gallery and you don't need to scroll through thousands of photos looking for a tiny icon to find the ones that could possibly still be pending. I think this is better and can't wait for Google to roll it out to everyone.