[/list] Or if you wish the image to display directly then...
[*] For inserting and displaying an image in a reply... the 'Insert Image' button
which gets you the following dialog.
[*] Right-click the picture as it's displayed on flickr.
[*] Select & click the 'Properties' option on the context menu.
[*] Select and copy the text listed in the 'Address (URL)' field on the properties page.
[/list][*] Paste the copied flickr URL into the URL field as indicated in the above image.
[*] Then click the 'Insert' button, and you wind up with...