Earlier quoted context omitted.
All buttons and links need to shift around for a good 10 seconds before the page settles.
This. My favorite is when I search for products on a website or app and the results appear in batches, with subsequent results interleaving with the previous results. So when you want to select a particular result and start to move your mouse and click, or move your finger and press, you often end up selecting something unintended because a later result pops into the location.
I do this in the gmail mobile app all the time thanks to their ads injecting themselves in between the emails several seconds late. They must love me, their most engaged ad consumer.