A pound every other day is 3.5 per week - only slightly higher than what IP designs for. If you are eating adequate protein, you will not likely lose any muscle. If you are starting at a higher weight, you will likely lose faster.
Make sure you are getting your fat. I don't know what the nutritional analysis is of the above but please, please get your 2 teaspoons in. IP has the 2 tea PLUS two Omega-3 capsules. I personally prefer a tablespoon of my favorite Omega 3 liquid, Barlean's (no fish burps, haha). Vitamins A, D, E, and K all need fat to be absorbed and used in your body, so you MUST get some in. Your brain is mostly water and... fat. Love your brain, eat your healthy fat.
End of loving rant.
Don't be afraid of switching to two whole eggs for breakfast for that healthy addition.
If you want to slow the loss down, add a few carbs. IP is not zero carb, packs can be up to 16-17g or carb per. So far my best estimate is I run 30-50g carbs per day depending on the day (including "slightly off" days) This extra 120-200 calories/day plus fat will slow you down that half pound. I'm not sure how many carbs are in your shakes, hard to say from here. Calories from 2tea of healthy fats will give you another ... 140 calories/day as well. These are well spent.
Also keep in mind IP is designed to have you regularly taking in veggies, getting used to it, and hopefully figuring out how to
enjoy them so you can keep eating them after phase off! They also keep your bowels moving which is important on a diet with protein and not much else. The clinic I went to recommends an extra salad in addition to the 4 prescribed cups. Constipation is a very common side effect, keep the stool softeners handy, if i don't eat enough veggies I end up in that boat. Water is a must as well.
The other huge need I don't see met is electrolytes. Without additional electrolytes - magnesium, potassium, sodium - this WOE is more miserable. It's a deliberately unbalanced WOE we are signing up for, and electrolytes and very important. This will help with regularity as well. You didn't mention water or electrolytes at all so hopefully have have these covered and just forgot to say so!