Based on my admittedly layman’s reading of these documents, they constitute non-exclusive subsidiary-rights licenses based on the exchange of either money or goods for those rights, not transfers of ownership. What Polaroid acquired by that exchange appears voluntarily restricted on Polaroid’s part to “the right to republish my image(s)” and/or “the worldwide non-exclusive rights for exhibition and editorial (non-commercial) publication purposes of the following images in perpetuity.” Since these letters of agreement and release forms originated with the Polaroid Corporation, we can reasonably assume that their terms represent what Polaroid sought to obtain from the photographers with whom they chose to collaborate in this way. […]