Many of my friends do this. I don't really get it. I enjoy seeing pictures of my friends' travels, but food pictures don't do much for me unless I can eat it...
I don't get it either. I hate to admit being so mean, but I've joked with a friend that I'm surprised a particular person we know who posts descriptions of every meal she makes doesn't post an "after" pic the next day of the toilet!
That's one of the reasons I deactivated my Facebook account years ago. Some people find themselves endlessly fascinating, posting every burp, fart and meal. Not necessarily in that order.