Go into your account, find the picture you want in the album. Place the mouse on top of the picture you want and a box will appear under that pic. It will have 4 parts to it. Each is a image code for different application. I think it is the bottom one you want.
Move your mouse down to it and click on it to highlight it. Right click and copy that whole line including the .JPG at the end. Then insert that into your message on MM. Try that, one of those 4 will place your picture into your message.