This was explained before.

When you type in the text part of your message and then want to add pictures ,when you check the box to attach files or pictures and hit the "upload files or pictures button" the text already entered gets submitted immediately and is viewable by others before the pictures are added. Once you upload the pictures and click "I'm done uploading attachments" then the pictures are added to the text that has already posted.

The text gets submitted automatically before the pictures get uploaded when you click on the "upload files or pictures button"

Everyone that participates here seems aware of how this works.

If you posted something you did not want to you can always edit your post and simply delete everything in the text area except for a period or single character (you can't submit a blank post.) then hit submit.

You can also ask an admin. to delete the entire post.