If everything normally works at Google, a Post may be rejected when a guideline is broken. This usually involves using a forbidden word in the text of the Post or an image that does not meet Google Business Profile Post guideline requirements.
These Posts guidelines are in addition to the normal Prohibited Content guidelines specific to Google.
If your Post has been rejected, I encourage you to read through those two guideline pages to ensure your content and images comply.
Some of these guidelines are not very clear; for example, “Superimposed text or graphics, including promotional content such as logos, are subject to the following requirements: For 360 photos, superimposed content must be limited to either the zenith or nadir (top or bottom 25% of the equirectangular image), but cannot be present in both.”
However, most points are pretty straightforward; for example, including email addresses, phone numbers, social media links, or links to websites within the content of your post will cause the Post to be rejected.
The image and video guidelines explicitly say that stock photography is not permitted: “Stock imagery, or photos or videos taken by other parties, are irrelevant and may be removed. If the primary subject of the content is irrelevant to the location, it may be removed.”
That’s an unfortunate policy, but technically, using a stock photo can cause your Post to be rejected. The algorithm that checks for stock imagery seems inconsistent, as many business owners and agencies continue to use stock images in their Posts. Perhaps the library of stock photos that Google has at this time is limited, however, but will probably be enlarged in the future, so if a previous Post passed through the filter, this does not mean that it will continue to do so if you use the same image within another Google Business Profile Post.
There is still no way to schedule Google Posts for a future date within the Google My Business dashboard. If this is a feature you would like to have, dbaPlatform has a tool that can handle this, as well as cross-posting the same Post to many different Google My Business listing at once, which again is not something that the native Google My Business dashboard supports.