Why do images sometimes appear as icons?

I am confused how to attach images so that every one can see them. Could there be a sticky thread with some instructions?

If you are not attaching images but using a link to an externally hosted image ensure you post the url of the image itself and not the page the image is on.

In forum Settings / general Settings you can set the message editor to Enhanced Interface - Full WYSIWYG Editing which will have an icon to use to insert images. Use the Advanced options to use the paperclip icon to attach images/files

http://blenderartists.org/forum/faq.php?faq=vb3_reading_posting#faq_vb3_attachments

Thanks, I will experiment with the instructions via that link.

Thanks, I will experiment with the instructions via that link.
Update: suddenly I see all my pictures in the post now I am at the computer.
Yesterday someone said he couldn’t see the pictures.
And a while ago I was on my mobile, and didn’t see some pictures. I tried another browser on my phone with the same problem. Luckily most visitors are using a computer.
Any idea?

Might be a caching issue. Are you still running into this problem? What browser and operating system are you using when you have this issue?

I also get the issue (images posted by other people breaking at times).

How often the breakage occurs seems to vary based on the hosting website, I am using Google Chrome 64 bit by the way.