Explanation

Start with the second blank, which refers to little things inside the structures: flower pots, sink fixtures, and working windows. The word in the blank, then, must mean something like details.

Of the choices, only minutiae makes sense. Now work the first blank: The trigger while suggests you need a word that means the opposite of internal minutiae. Of the choices, external is the best fit.

While august might be tempting, it’s too strong for the context: While the structures are important, there isn’t any indication that they’re inspiring reverence.

Hence option B and D are correct!
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"While" indicates contrast with "Internal" ==> Best fit is "external"

Hint for 2nd blank
flower pots, sink fixtures, and working windows that make them truly magical. --> A word that describes a small thing, so "minutiae" fits best.

Hence, BD is the Answer