I think the generalizable point here is that, at least for me, but I think this is for everyone, it should be considered an important part of the "UX" that users understand the "state" of an application. In particular, what data has been sent and received.

For example, this is imho one of the most important features of WhatsApp, the little checkmarks that tell you, in one tiny little graphic, whether your message has been sent, received, or viewed. This is just so important to the user experience. I feel that app developers that ignore that users need to know what the app is doing, what state it is in, are just ignorant of human psychology and how we interact with machines. We don't want "magic", we don't want to "trust", we want to be informed and to know what is happening. Doing this is a streamlined way, little unobtrusive checkmarks for example, is UX gold.