This paper provides an overview of the research activities conducted at the Otto Rettenmaier-Research-Laboratory (ORFL) pertaining to mixed reality and digital twins, with particular focus on the potential for digital twins to support holographic interfaces. The paper considers the applications of this technology in the context of mobile robotics and industrial systems. It details the creation of a physically representative model of the digital twin and describes the establishment of communication between the digital and physical twins. This digital twin serves as the foundational framework for the mixed reality interface, which is designed to enable an interactive and intuitive operating concept. It also builds a bridge to artificial intelligence, in particular to predictive maintenance, predictive quality, anomaly detection, process parameter optimization and explainable AI, and how these technologies benefit each other.