All browsers cache certain page elements of websites that have been visited previously for a certain period of time. This is particularly true of images. This means that these elements of the page do not need to be downloaded again and it improves performance. Because you have most likely visited your website before it's possible that some changes will not appear on your website until you clear your browser cache of images and files.
Instructions on how to clear your browser cache can be found here: https://promotemyplace.zendesk.com/hc/en-us/articles/216230123-How-to-clear-my-browser-cache
Please note: Remember to check the 'Cached images and files' box to ensure that you don't lose any autocomplete data from your browser.