The quotations from paragraphs 4 and 5 contribute to the text by illustrating the negative perceptions some artists and intellectuals had of the Eiffel Tower during its construction. The phrases "gigantic black smokestack," "half built factory pipe," and "mast of iron gymnasium apparatus, incomplete, confused and deformed" suggest that these critics regarded the Eiffel Tower as an unattractive and poorly conceived structure.
Thus, the correct answer is:
They highlight how some people regarded the Eiffel Tower as hideous.
This reflects the broader theme in the text of the initial opposition and skepticism that the tower faced from various sectors of society, particularly those in the art community.