The porn video tag "feminization-pov" can be broken down into two parts: "feminization" and "point of view" (POV).
Feminization refers to a niche fetish in the world of BDSM, crossdressing, and humiliation where one partner is subjected to acts or scenarios that force them to adopt more feminine characteristics, often involving wearing lingerie, makeup, or other clothing items traditionally associated with women.
POV stands for "point of view" and in the context of a porn video tag indicates that the scene is filmed from the perspective of the participant experiencing these feminization activities. This usually results in an immersive experience for the viewer, as they are placed directly into the role of the individual being subjected to these actions.
So, "feminization-pov" would denote a porn video that depicts scenes involving feminization fetish acts and is filmed from the point of view of the character experiencing those acts.