hi!

A booktalk in the broadest terms is what is spoken with the intent to convince someone to read a book. Booktalks are traditionally conducted in a classroom setting for students. However, booktalks can be performed outside a school setting and with a variety of age groups as well. It is not a book review or a book report or a book analysis. The booktalker gives the audience a glimpse of the setting, the characters, and/or the major conflict without providing the resolution or denouement. Booktalks make listeners care enough about the content of the book to want to read it. A long booktalk is usually about five to seven minutes long and a short booktalk is generally thirty seconds to two minutes long1.

What does that have to do with author/venue pictures?

Good morning caloygwafo, and welcome to LT. There are lots and lots of groups, more than I've been able to survey. Each one has a short explanation of the sorts of interests to be discussed.
You might post in Book Talk or Librarians Who LibraryThing.

I love the booktalk concept. As far as I'm concerned "It's all about the book!"
But tell us what sort of discussion you're looking for.
I personally collect books with dynamite first pages in order to capture reluctant readers.