This Enterprise's appearance is based on the refit therefore the glowing dome is a sensor.
I don't think you have the first clue of how to make a logical inference. Let's see what's wrong with this short sentence:
1- You have no clue what the designers intended.
2- We clearly see in the movie that it's not a sensor.
3- The design is actually based on both the original and TMP versions.
4- It doesn't follow that every single element will be of the same nature even if (3) were granted. And that's even if the new design was _identical_ to the TMP one.
5- You don't even know if the original design had a sensor dome, because the only sources claiming that it is are unnofficial.
Wow, that's a lot of wrong.