Solid Holograms
This name is a slight misnomer. It is not a hologram in the usual Earth- laboratory sense, but rather a kind of photonic field, as photons are bosons. The ability to manipulate a Higgs field led to a revelation that certain other bosons could be manipulated in similar fashion, leading to shapeable photonic fields, dense enough to give the impression of a solid object when combined with certain other classified technologies.
Solid holograms can be overlaid on almost any object, including the human face. This results in the object underneath being perceived as whatever object the solid hologram is projecting. In the case of a small unit being used as a disguise, an additional scanning system underlies the solid hologram, reading the features and expressions of the agent and replicating them on the holographic face, thus enabling realistic interactions.