Would like to know how this is done in Flash MX

I’ve been looking at this for awhile and not succesfully duplicating this.
Go to http://www.macromedia.com/into/ and select [color=royalblue]LAUNCH THE EXPERIENCE. [/color]
[color=royalblue][color=black] When the flash is finished loading scroll your cursor over any image and you will see the callout fade in and size itself. [/color][/color]
Can someone give me some guidance on how this is done.?