Your comment has made me think about Roland Barthe's distinction between the 'studium' and the 'punctum'. While the studium of a photo can be understood with historical/social/cultural context, the punctum conveys meaning outside of any symbolic system. Something in a photo can just make you feel something for reasons that may elude you.

I wonder if the wheelchair in this photo can be considered as a 'punctum'. I don't know if I understand Barthes well enough to make a call, but it seems to fit the bill. There's something about the wheelchair being situated next to the motorway that is incredibly haunting, but I don't think it could count as a a 'studium' because we don't really have any historical context, so we end up projecting our impressions upon the image.