Images, Websites and Caching
The reason profile images may not appear immediately after updating is because your browser will “cache” data to make the website pages upload faster. This cached data is used as reference for your browser and sometimes, the new information you added to the site (like an updated photo) isn’t recognized right away.
The internet browser is working to give you the fastest interaction with the internet it can provide. Remembering or caching the information on a website allows the page to load faster, therefore making your experience on the internet faster. This sometimes means that your internet browser will assume the information on the page is fresh and not look for new information on the page. To prompt your browser to look for the new information all you need to do is refresh your page so that your browser will reload all of the page information, including the data heavy images.
This only happens to users that frequently use your website, new users would be able to see the new photo right away because their browser has not “cached” any data from your site.
You can clear your cache by using your browser settings. You can check out the links below for more information on clearing cached data for your particular browser.