You've reach the appropriate rank to be able to post picture. Newbie is the only rank that are not able to post images. They need to be a copper member in order to do that.
Thank you for the information, although I must search "How to upload the pic in bitcointalk?", but now I have known about that because of your information.
You must have a minimum of Jr Member level or Copper membership to display images.
https://bitcointalk.org/index.php?action=credit;promote
You upload your picture to https://imgur.com/upload and copy the link.
Clicking on the icon above that looks like a picture will produce the code or you can manually type it like below.
Code:
[img]https://i.imgur.com/BFvHPTt.png[/img]
This:
Will look like this:
