Where do I edit what the TT logo looks like when link is pasted in Facebook?

I have a private FB group for den that I use to communicate with parents. When adding a link to our latest calendar event, the logo posted with the link is very bland and plain (see attached). Is it possible to dress that up a bit somewhere in the TT settings? If so, where?



Bumping this to see if I can get a response.

I was just about to ask the very same thing.