With the increasing use of organic light emitting diodes in lights, smart phones, wearable smartwatches, and computers, visible light-based device-to-device (D2D) communications has become more and more relevant. We propose D2D communications using smart phones’ display pixels and their built-in cameras. We investigate the impact of receiver orientation and user mobility on the link performance. We derive a Gaussian model for the probability density function of the delay spread and optical path loss (OPL), and show that the channel delay spread decreases for a typical furnished room compared with an empty room, whereas the former has an increased OPL. In addition, we show that for the case of a furnished room and considering user mobility, the peak OPL values are about 64 and 62 dB, with and without considering the receiver’s random orientation, respectively.