I, Gollgagh said in post #1394583:
Guys, sexual dimorphism is when the males and females of a given species have distinct characteristics; Nidoking and Nidoqueen would be an example of sexual dimorphism; Pikachu isn't changing sexes here, she's evolving. [...] I feel that the tag really ought to be used when showcasing the differences between sexes, not just when a gender-specific characteristic is visible on a single character.
I just really feel that the tag is warranted for stuff like post #989657 and even post #876492 because they are showing the difference between sexes, but not ones like post #1282086 where the point of the picture isn't "Hey Guys, this is a female Raichu, okay!"
Updated by jxh2154