There is no such thing as an animated JPEG.
What you are seeing is an animated GIF served with a URL labelled .jpg.
The user just put the wrong file extension on the file.
Yes, I know.
Am wondering how this is getting around Facebook though.
And yeah, I've had some of my proteges already emailing me about it.
not making drama - just wondering what the community here has to say about it.
someone just links the misnamed file - no mystery.
No mystery, the browser is just looking inside the file at the content, determining it's a renamed .gif file, and interpreting the contents as a .gif file. Apparently Facebook's software is not so intelligent as to be able to do so.
Look up "Mime Sniffing" in browsers some time.
This are not renamed GIF files. For the Example i got this image
It's animate in the FB with no problem, & I right click (on the Firefox) select View Image it redirect to me it Original origin https://fbcdn-photos-h-a.akamaihd.net/hphotos-ak-ash4/396036_479136468765642_1494364208_s. jpg it say *.jpg as it's extension. After that I right click it & Download it, there's the Problem. It's Only Downloading 1st frame Only & It's also a JPG image. It's like that animation contain several images & Script those with Time Sync. I don't know how it's done. But surly this is not a renamed GIF file. I really, really want to know to do this. Any one Help PLZ.
Of course it's a renamed GIF file. Open it in a text editor if you don't believe us. The header says "GIF89a".
It's a rewrite rule you can do as a webmaster (using server side scripting).
Simple explanation in human language:
"Hi (my) website,
Would you please replace every extension that ends with ".gif" by ".jpg"
on - well, let's say - every page
without things breaking up?
"Dear webmaster of mine
No problem, but you do know that those are and will still be ".gif"-files even if I replace the extension in the shown url?
"Hi again dear website
Yep I know, no problem. Let's just hope it won't fool people
Hope this solves your riddle