How do people get to 'like' my picture if I don't know them?

[katkouta]

I posted a pic today to a wall of a group I'm in (which these people aren't btw) and have had a few 'likes' from people with whom I have mutual friends.The mutual friends haven't commented though so I don't understand how they got to see it IYKWIM.
It's not that I mind just want to know how they got to see it?

Your photos are on the visible to friends of friends setting. Go to your privacy settings and adjust.

Did you tag those friends? If so, their friends can see them.

Or as wheres said, you have the photos on friends of friends. You can adjust individual photos or a whole album of them via settings.

No, my photos are set to friends only, and I didn't tag them. Thats why am

Is the group open to public so that even people who haven't joined the group can see the wall? Obviously anyone who can see the wall of the group can see the photo.