[This is a modified, and simpler, form of the maneuver.]
Aha! I have contrived a subterfuge to have an image centered on a post. This only applies to forum sections that allow uploading of images.
1. Upload the image.
2. With the cursor on the line where we want the image, use the "Align" tool from the composition toolbar and choose "Center". The cursor will become centered (a property now of the line).
3. Select the "thumbnail" or "full image" insert button by the uploaded image.
4. The image will be centered by inheritance from the properties of the line.
Here is an illustration:
Other characters in La Bohème (including one of the principals)
Here, I will use the "full image" presentation:
Bethany, the assistant stage manager, doing "craft service"
I note that clicking on the "thumbnail" opens it in large size in the "alternate viewer". Clicking on the "full image" does not.
Best regards,
Doug