The lower feature is slightly further aft than the one above, which would indicate a slanted intermix chamber.
Only assuming that the domes have anything to do with intermix chambers. A slanted chamber would be required in the Enterprise
as well, if such a connection existed.
The bottom feature does not have a protruding central dome, but the sunken structure has a design quite similar to the top dome:
Similarly, the Constellation
class features two lateral domes, but neither is distinctively painted let alone lit: these Enterprise
kit components are simply painted over. Yet their role may well be interpreted to be similar to that of the identical component seen lit on the Enterprise