This is from their Christmas electical catalog, its on the back page - cant find this catalog online as yet. It has Ipod pictures on the front page, with heading "for the gift of entertainment"
This equates to a 25% saving like the other deals from Aussie post, and kmart (which ends today)
The difference is that these are $20 cards unlike Aussie Posts which are $30 cards - this gives you a little more flexibility if you want to share them around.
Edited - JeffreyM: Edited link to direct catalogue page/picture link.