You're allowed to post later, though this will be visible with your post. Tbh I like it until now. It's a good way to engage with my friends now that I only see them a few times a month. The friends I have on BeReal are generally respecting the rule that you either post at the moment BeReal asks you to or at the nearest moment where it's okay to so. I won't post at work, at the toilet, or in the shower or something. But I will do so after those moments of I'm doing something mundane like washing the dishes or cycling home. You'll generally just get a sense of what your friends' life's like like normally, as well as the fun things they do like traveling or visiting some event.