Meanings of sharing 'family and children' pics on FB

I wonder when Facebook was originally built it carried the tag 'social media'. But since it was meant to become a virtual hangout for friends, typically from a college, it isn't a surprise that it assumed the tag so easily.

Given the current situation, the meaning of 'social' can be talked about until...

Given that the connections to most 'friends' on FB now are at best tenuous, I am trying to make sense of the sharing-family-and-children-pics-(with all the friends)-on-Facebook phenomenon.

1. Sharers know that friends might want to know what's happening in the family. Though these sharers don't know who these friends are exactly. So anyway, the pics should reach these not-exactly-known friends who might want to know.
2. Sharers know who these friends are exactly but don't find any other channel suitable enough to do such sharing. 'Suitable' means convenient or sophisticated or common channel used by all friends.
3. If in point#2, I pick the aspect of convenience, I can conjecture that sharers find it inconvenient to build a channel where they can do the sharing with just those friends with whom they want to share.
4. Sharers find it a matter of pride to show off their 'families', whatever the context.
5. Sharers are not exactly content sharing their moments and space with those they find themselves with. They want the moments and the space of togetherness to spread among other friends too. And who these other friends are, they might or might not know exactly.

It isn't very tough to reproduce. And it isn't tough either to take smiling pics every now and then. And it isn't very tough not to know exactly with whom to share smiling pics of those that we reproduce.

What's tough often doesn't get addressed, nor shared.