Explanation

In the part following “since,” the first sentence of the paragraph suggests that the subject matter of portraits might not seem to fit with the idea of “high art.” So the suggestion is that the presence of portrait paintings in art museums is in that sense odd or unfitting. Of the choices available for Blank (i), “surprising” is the one that expresses this sense. The second sentence, in contrast to the first, offers a point in favor of portraits
— “artistic skill.” So the second sentence is offering a reason why portraits should be in art museums. Of the choices for Blank (ii), “justifies” is the one that completes that thought.
Thus the correct answer is surprising (Choice A) and justifies (Choice E).
_________________

why the answer is not irrelevant? because it is the portray is closer to family. I mean the classification is indifferent

A , E

The author of the sentence is wondering why so many painting are into the galleries of art nonetheless they are more than a photo and NOT a real piece of art.

In other words, he / she is sarcastic in somehow.

It is (i)_________ that so many portrait paintings hang in art museums, since the subject matter seems to dictate a status closer to pictures in the family photograph album than to high art.


A is the answer for the first blank

regards

why not irrelevant