Diplomacy often operates in mysterious ways. Take, for example, the recent visit of the senior Iranian official (president Hassan Rouhani) to Italy. Rouhani trained as a cleric (like so many other Iranian leaders) but spent most of his time studying and teaching law. He earned a doctorate in law and a British university (in Scotland) between 1995 and 1999. He became quite familiar with Western culture. Since going into politics he has been working to develop better relations with the West while also trying to reduce the influence of Islamic conservatives over Iran politics and daily life. Many of the more radical of the Islamic radicals in the Iranian government consider it blasphemy for Rouhani to even visit the West. Some of these critics believed the visit makes Rouhani unfit to be president of Iran. This sort of accusation still carries some weight in Iran.
One thing Rouhani, and many Western diplomatic officials have learned from past visits by Iranian officials to the West is that if these visitors are photographed doing anything that could be interpreted (by Islamic conservatives back home) as blasphemous or un-Islamic the visiting official would face much criticism and loss of power and influence back home. Those who are many familiar about how this works, it was not surprising that when Rouhani visited (at his request) some museums full of centuries old statues and paintings the ones that showed any nudity had the naughty bits covered. While this seems absurd and demeaning to the average Westerners (and some Iranians) it is seen as a defeat by Islamic radicals in Iran waiting to pounce on Rouhani for viewing such decadent and un-Islamic art. Covering up the nakedness deprives Iranian Islamic radicals neutralizing or bringing down another Iranian reformer.
Sometimes what looks like a retreat is actually a victory. This applies in military as well as diplomatic affairs.