Gender Adoption
The most comon name for this is a mirage. Another such image, differently caused, is called a virtual image.
An image shot horizontally is called a landscape photograph.
Just that: reflection. There can be a virtual image, an imaginary image, an inverted image etc depenting on the shape of the surface of the mirror.
Because the image is not real. The object is not really there, it's only virtual.
Gender Adoption
A pig is either male or female. A male intact pig is called a boar, a male castrated pig is called a barrow, a mature female is called a sow and an immature female is called a gilt.
That you are mature capable and approachable
A mature female turkey is called a hen.
a mature human egg is called an ova
A mature female goose is called either a hen or a goose. A mature male is called a gander.
A mature male pig is called a boar. A mature female pig (that has produced offspring) is called a sow.
Just 'the mature stage'.
It is called "image".
Mature female pigs are called sows.
A mature male sheep is called a ram.
Lamb - there is no different between gender. Only when they are adults is there a difference.