I would suggest opening up a
http://www.flickr.com/ account to store your photos if you have a lot of them. Then you can use the "insert image" button on a post in here and link them from the Flickr account.
Most of us don't attach photos here, we simply link to them. It may also be that the file size of the particular image is too large for this site. Another reason to use an external method for showing photos on here.