I can't give an exactly accurate answer but my guesses are next:
1. Either there are later preproduction of 7886 set, where Lego silently changed the torso. (2 photo)
I don't know and can't say how long this set was in production at the Lego factory, my suggestion is 1-1,5 years, so there could be changes in torso during this period of time.
2. Or is it a big production of sets with torso missprints (1 photo), because most of people have this minifigure exactly as in the first photo (with just 2 white torso outlines, left and right). You can judge that by viewing the Youtube reviews of this set and watching the Google Photos.
And most like this is was first wave of this set, so this is why most people have Harley like on 1 photo.
You also can notice an different torso print variation on official render on a set box.
Also, official render of set himself had Harley like on second photo.
Talking about owning of set: You can saw photoreview of this on Flickr by Hamid (KatanaZ), he has a box from the set and the set itself. -> https://www.flickriver.com/photos/10335017@N07/50232481666/
Well, the conclusion is next - Most likely this is a variation of torso, where 1 photo is common, and 2 photo of Harley is rare print variation, that comes in later production of this set.
Bricklink has no information on this, and the internet too.
As i said at the beginning, i can't give an exaclty accurate and 100% answer, this is just my guesses, which are more like the truth. (i hope)
Even Lego in encyclopedia don't know what torso to use...