Is this the same person?
nope! Antonia's icing is a royal icing. Alice's is more of a glaze icing (correct me if I'm wrong, someone!). I haven't tried Alice's, but I love Antonia's...especially when paired with the no-fail sugar cookies. Adds the perfect amount of sweetness!
Alice's icing has a bit of butter in it, adding some flavor and a little softness to the icing. It will still dry firm, but not crunchy. It does take a bit longer to dry. In my experience, both icings work great. If I am in a hurry, I prefer royal (with flavoring) because it dries quickly.