The big trend (rightly so) in web design right now is making your website responsive. Meaning that your pages will look good on any size screen. As a ux/ui developer I always initially test my pages by grabbing the side of the window and resizing it to see how the page reacts. Depending on your content and its priority to different size screens you may sometimes have to make drastic changes in your layout occurring as the page scales down. For example lead images may disappear completely, nav bars may collapse and float to a different part of the page, unordered lists may get transformed into drop down lists, etc.
Whats the problem?
When resizing the window and watching your page adapt some of these changes may be confusing. If you weren't paying attention for a split second you won't notice the navigation bar you've been using this whole time turn into a hamburger menu in the corner. It also may be a little disorienting, the hiding and moving of elements may cause flickers or shifts on the screen that make you lose track of them.
How to handle it?
So I was wondering how important is it to design not only for users landing on certain screen sizes (mobile, desktop, etc.) but the users that resize after page load. Should you ease elements in and out with transitions, provide some blink/impact animation when the elements lands in its place so users see it, some indication that you hit a breakpoint and the layout is different? Or will average users not pay attention to the transition period and only care about the page layout when it's stationary.