What is this unknown cable for 13" MacBook pro?

[autotran]

Model A1278 13" 4/13/2010 - 2/24/2011 S/N 340481VMATM
It came without a hard drive and optical drive and has broken or missing HD & Optical cables which I an able to replace. I have 3 15" and 2 13" 2008 to 2011 models (the other 13" is broken and I also have a broken 2014 model) and this is the only one with a cable like this. Thanks, Dave

 

[Cory Cooper]

Hello and welcome.

That looks like the camera connection cable, which normally routes to a connector on the logic board to the right of the optical drive and just below the fan.

C