Within the intricate tapestry that is Chinese folk belief two ideas of protection stand side by side, the City God and the Door God. Of the two, the door god is most frequently encountered in two-dimensions; it’s in the name. One must imagine that within the framework of this belief, these are the actual gods, not merely depictions of a deified entity.
Both function as protector of thresholds and boundaries, but at different scales and with varied functions. The City God emphasizes local jurisdiction, leaning toward administrative order for cities, towns, or communities. So one might equally encounter them in the form of statues. The Door God emphasizes threshold protection, leaning toward building entrances and window sills, and while one can imagine small shrines and statuary, much more common is the Menshen (神荼)