Actually, the image you are trying to use doesn't exist. If you try to access it directly (https://www.drupal.org/files/issues/expert-back-end-development-Forcontu-badge.png), you will get a 404 error. The image used from the other account is https://www.drupal.org/files/logo2104april_0.png, and it exists.
The markup used from that biography is the following one.
Web developer, Drupaler driven by passion, love to navigate new technologies and integrate them in Drupal.
In your biography, you should use the following markup, if you want to use the same image used from the other account.
<a href="https://www.forcontu.com/en/certificate?field_s_certificado_id_value=D8BD0341&field_s_certificado_codautentica_value=f2e44" title="See the Certification"><img src="/files/logo2104april_0.png" alt="Drupal Certification" title="Forcontu Expert Back-End Development" width="140" height="140"></a>
I take the image you see (https://www.drupal.org/misc/watchdog-error.png) is used as placeholder also in the case the referenced image is not found. The tooltip is clearly wrong in that case, but the input filter used from Drupal.org uses that tooltip even in the case the image cannot be found.
As side note, the images attached to a comment in an issue were once uploaded to the /files/issues directory, but nowadays they are uploaded to the /files directory.