Friend of friend liked my status on facebook, just curious?

[john]

Hi, I haven't logged on to my facebook for months and today I noticed certain changes (or not) on the notifications.

For example, I posted a status update with Jacob tagged with it. There were several of my friends and also his friends (whom are not on my friends list) 'liked' the post.

Then, after I logged off for several hours and returned back, I got another notification of one of Jacob's friend, Jack (not on my friend's list) 'Liked' the post. However, the notification read:

"Jack (friends with Jill) liked your status"

Jill is on my friends list and I often communicate and looked at her status.

What I am wondering is why Jill's name appear on the notication and not Jacob's.

Thanks.

ps: sorry I know this confusing. I am just curious.
Jill is also Jacob's friend.