Go to 'Go Advanced', then to 'Attachments' (Safety pin sign). Upload your image, close the window. Go the 'Attachments' again and then add it in your post.
Nothing worked for me, i tried everything, wanted to post pics of my CA plus 15000 ltd edition, CA TRD LTD EDITION and my old LAVER & WOOD Signature bats but couldn't succeed in posting pics, finally gave up, very sad.