Do you mean that the issue is the fact that they're brothers or that it's been printed in a newspaper with their faces on? Because if they're two consenting adults, they cannot reproduce with one another, and they didn't grow up as siblings, then I too am struggling to see what the issue is, considering that the usual incest-related issues (inbreeding and consent/coercion issues born of familial bonds/hierarchies) are addressed. Seems the only remaining issue is that it's been publicized, meaning they're liable to get shit on by the people for the rest of their lives for something they weren't aware of, had no control over, and hurts no one.