XF 1.3 How do I edit "this" image?

[Okenyon]

Guys on Macs you can bookmark sites and they show like the attached.

I have some other forums who have a custom "image" here what is it and how do I change mine please?

 

[Paul B]

See point 7 of the FAQ: https://xenforo.com/community/threads/frequently-asked-questions.5183/#post-180456