My recent pictures in my Facebook Messenger album is showing a picture from over a year ago, why?

A

AC Question

My recent pictures in my Facebook Messenger album is showing a picture from over a year ago

So I sent a picture to a friend in December 2014 via Facebook Messenger. I didn't even think the photo was still on my phone to be honest. This morning I noticed it showed up as my most recent photo, and when I looked at the date, it said I RECEIVED the photo July 26th 2015. This makes no sense at all. Not only did I not receive the photo in the first place, but the date is also terribly wrong. I'm very confused and for other reasons it has caused me stress. Is there a glitch or something? What is going on here?