You updated your Image but are not seeing it online?
You may need to empty your browser cache because chances are that the image has been cached. Sometimes you may need to actually restart your browser as well. Safari especially is very agressive with caching content.Another good thing to try is to open your site in a different browser that you do not normally use.
If you are using a service like Cloudflare, then it may take some time for their cached to get refreshed with the new image. You can also manually flush the cache with Cloudflare, or enter your site into Development mode.