Is it permissible for a Muslim to photograph himself or others in the Two Holy Mosques, or with a famous person, and to publish that on social media? And does this fall under the category of showing off (riyaa’)?

Photographing oneself inside the Two Holy Mosques follows the ruling on photographing living beings. So, whoever permits it absolutely may do so here, and whoever prohibits it should be even more cautious in the Two Holy Mosques. As for photographing with actors, dancers, and the like, it is not permissible, as it involves showing reverence and appreciation for them despite their open display of sins. Similarly, photographing unrelated men and women together is forbidden. Merely photographing a pilgrim or an 'Umra performer in the Two Holy Mosques, alone or with a famous person, and displaying it on social media, does not necessarily deem the doer ostentatious (riya'). Ostentation has no outward signs, but the act might stem from ostentation and seeking reputation, for polytheism (shirk (definition)) is more subtle than the creeping of an ant.