One thing I do not like about Skype is that it is slow to react.

When a new message has arrived, the Skype taskbar button displays an overlay icon and flashes to indicate this. This is all good.

Since the Skype icon is the fourth icon on my main computer (as well as on my laptop), I press Win+4 to read the new message. Most often, this takes me some half a second, and when I am done I press Win+4 again to resume my work. But after this, the taskbar button still displays the overlay icon:

The problem is that I am too quick for Skype. Apparently, the software is programmed to remove the overlay notification icon after the message has been displayed for a second or two. Hence, I have to press Win+4, wait for a while, and then press Win+4 a fourth time.

Clearly, Skype is designed for people who are processing data more slowly than I am.