What is flexible media? -Jon Loomer Digital

Some advertisers are seeing a new feature in Ads Manager called “Flexible Media,” not to be confused with “Flexible Ad Format.”
what is it? How does it work?
Let’s discuss this…
where to find it
When uploading a single image or video, you may see a checkbox with the following message:
Enable flexible media to deliver the media you select below to other placements when it may improve performance.
You can also see it under uploaded media during ad creation.
If you hover your mouse over it, you can turn it on or off.
How does it work?
I haven’t found any official documentation about this, but my explanation of flexible media is this…
You can provide different creatives for each of the three placement groups (1:1, 9:16, and 1.91:1).
For example, you might provide a 1.91:1 image for the right column and other placements in its group. If Meta believes you can get better results using square, it will test that too.
As far as I know this works for all targets when using a website to convert a location and a single image or video. Since I haven’t found official documentation, this might just be a test.
Do you have it?