If you had guessed while reading the previous comic that they had switched forms, give yourself some manner of treat. A cookie, perhaps? Maybe a dune buggy? It's your choice, really, seeing as you'd be giving it to yourself.
This does mean that there is now a Grace clone form, and that it does, indeed, give a person Grace's antennae. Are they as fancy as Grace's regular antennae? Heck no. You're not going to be levitating anything with those. You can certainly move them around and stuff, and they probably feel super weird, but they're mostly just for show. Still, it's an accomplishment for Tedd that they're even there at all.
Commentary added for December 31, 2014