Indeed, yet they didn't ask - it was assumed. Both parties assumed. Equally so it's not too much to ask for someone to state how private or public an image or piece of information is. This is really why it's up to the individual to keep things private when they truly want them to be. There is no real thing called privacy. And human behaviour on average dictates that a) people make mistakes and could share things they might not mean to, and b) that many people, the less close they are to you the more so, that will not think about being able to easily share something (perhaps unless expressly stated otherwise in that moment).
