So I want to add a picture to a post for the front page (using xenporta) and when i put it in the with imgur and post it all it does is replace my profile picture for the post on the front page. Example is the first post HERE.
Your Avatar is simply a placeholder for the recent news block when no other pictures (Attachments) can be found. I personally like it this way since it gives the news block some type of image even when there is none. If your promoted thread has more then one image it will pull them all depending on the character limit you set in the ACP options.
When you promote the thread there are options behind the calendar that will allow you to do just that. Click away the calender and select either 'Avatar' to include an avatar or 'Disable Promotion Icon' for no avatar. Both these options will leave the embedded image within the main body of the promoted post.
Then you have to not upload a image attachment, rather use external images or something. If you manually promote threads you can configure it, there is nothing that changes the default behaviour, AFAIK.