OK, the images posted are
really creeping me out.
But have a happy birthday, "Mate"
(meant in a real manly, not at all homo way).
According to my Australian-American translation encyclopedia, for your birthday, you should have a can of Fosters or two, "chunder" (no translation available, probably having something to do with your "mate"), then drink something really good.
You Aussies do have some really weird customs, I must say.