Background: Stack Exchange now lets you paste images from the clipboard into the image upload dialog. Unfortunately, there is no indication that an upload is going on. I am wondering if this is really bad UX or it just affects me.
There are generally some functions in an app that take an unpredictable amount of time. Let's take an upload for example.
Is it OK to omit any indicator of the fact that the upload is indeed in progress? It doesn't matter if it shows how much the upload has proceeded, something like which says "Something is going on, please wait. There is no need to keep clicking that button." is fine as well. I'm comparing situations when you press a button and nothing happens until the upload (or whatever) is complete.
Is this a bad UX decision? Have there been any studies on this?