What happened was a deliciously icy coffee hit. It's easy, you should make it next time you do brunch. Of course you can fancy it up with cream, chocolate sauce, vanilla and the rest.
Cup of cooled strong coffee
Defrosting milk (leave a frozen 1l carton in the fridge over night) It should have milk icebergs still in it
Sugar to taste
Go 3/4 coffee and 1/4 milk.