Hm - I also see the default ghost icon at both https://blog.arielmiki.xyz/favicon.ico and
https://blog.arielmiki.xyz/favicon.ico/ - are you sure you successfully uploaded a custom favicon in Ghost following these instructions:

1. Login to Ghost admin panel
2. Click General
3. Under Publication Icon upload your favicon.ico
4. Click Save

Two other things to consider:

1. Sometimes image file uploading will fail in GHOST because it doesn’t have proper write permissions on your server, test that uploading other files (like photos in posts) works to eliminate this as a possibility.
2. Browsers cache favicons, HEAVILY. So even after you change your favicon and even after you see the correct image at https://blog.arielmiki.xyz/favicon.ico, you may continue to see the old favicon in the browser tab, sometimes you just to close and restart the browser, or try another browser to confirm the new image is working correctly.