What can you tell about the state of margarine in this cookie?
If I am looking at the same things you are when you describe the "freckles", they look more like debris from shattered chocolate chips than any artifact of the dough ingredients. How did you shape the cookies from the frozen dough you purchased? Was it in the shape of a log that you sliced? If so, that cutting would create small chocolate chip particles on top of the cookie that would look like those freckles when they melted during cooking.

As far as the shininess on the top of the cookie, that can often be caused by an abundance of sugar in the dough. Especially since they look to be slightly underdone.

I am curious why you are focusing on the margarine in this dough and comparing it to what happens when you make cookie dough at home. If this is commercially produced frozen cookie dough, there are probably many industrial ingredients and other additives in it that you don't use at home, and these can cause effects very different from what you are used to in homemade chocolate chip cookies.