I logged onto my main desktop the other day and all of the desktop icons were a lot smaller than usual:
I had no idea how this had happened; I have syncing set up with OneDrive and had recently installed and configured an old laptop with a 1366×768 display and my main desktop is 2560×1440 and my initial thought was it was down to this mismatch. However, I couldn’t find anything which looked like it was the cause of the problem.
I resorted to an online search, but didn’t immediately find anything. I did stumble onto the resolution and this was probably what cause my problem initially.
On one web page, I zoomed in using Ctrl+mouse scroll wheel, but didn’t have my mouse over the browser window, but over my desktop. The icons on my desktop became even smaller; reversing the direction of scroll the icons became bigger again:
I’ve no idea if you’ve always been able to zoom the desktop or if it is new, but now I know, I can be more careful when zooming in on a website. and make sure the mouse cursor is over the browser.