The sonnet belongs to a collection of poem by Shakespeare. It has the typical structure of the English sonnet, indeed it is organized in three quatrains which tell about different aspects of the same problem, and the final couplet. 

A woman's face with nature's own hand painted,

Nature is compared to an artist who creates the fair youth’s face as a woman’s face. But his beauty is better because he hasn’t the defects associated with female beauty.

Hast thou, the master mistress of my passion;

The reader can do different conjectures about this statement. Maybe the Fair youth has the physical characteristics of male and woman or maybe it isn’t important that the owner of speaking voice’s passion is a woman or a male.

A woman's gentle heart, but not acquainted

With shifting change, as is false women's fashion:

It is a Proverbial characterization of women in general. The fair youth had a woman’s gentle heart but he is better because differently by women he is constant and he doesn’t change his love continually.

An eye more bright than theirs, less false in rolling,

His eyes are handsome as women’s eyes but they are deprived of malice.

Gilding the object whereupon it gazeth;

His eyes have a quality: they light up everything. He is the cause of the speaking voice’s raising.

A man in hue all hues in his controlling

Which steals men's eyes and women's souls amazeth.

The general sense is that the youth is a man in appearance, embracing all manly features in himself; but his appearance is so sublimely that all are subjected and are dominated by him and his beauty.

In the renaissance, the concept of beauty is composed by physical beauty and psychological balance.This statement confirms that all people are subjected to the Fair Youth.

And for a woman wert thou first created;

Till Nature, as she wrought thee, fell a-doting,

Nature initially created The Fair Youth as a woman, but her creature was so sublime and Nature fell in love with him. So She decided to transform the Fair Youth into a man. Indeed Nature is connoted as a woman.

And by addition me of thee defeated,

By adding one thing to my purpose nothing.

To transform the fair youth from man to woman, Nature added something that was without value for a man but guaranteed woman’s pleasure. The speaking voice clearly refers to the male reproductive organ.

The sense of this statement could be that he loves the youth as a man loves a woman, so the male reproductive organ have not any sense, indeed he would prefer him to have a woman's body.

But since she prick'd thee out for women's pleasure,

Mine be thy love and thy love's use their treasure.

The sonnet ends with an invocation that the poet makes: he wants to enjoy the fair youth’s “spiritual” love. He wants to leave an ideal love with him.

The speaking voice says that the object of his passion was painted with the face of a woman by Nature. He also means that his love connects male and female beauty in a single subject (the Master Mistress of my passion). In portraying  Shakespeare says that he has got the gentle heart of a woman even if his heart is not used to shifting and changing the object of love as women do. 

Talking about the fear youth's eyes he says that they are more shining  that the ones of women and in addition they are less false because they don't roll around so often. His eyes make the object of his look nicer. Besides the colors of his fear youth control all hues. As a matter of fact he captures all women's souls and at the same time he manages to steal men's eyes. The speaking voice underlines how at first Nature wanted to create him as a woman, but his creation was so beautiful and Nature is a woman too, so she fell in love with her beauty and therefore added something that was without value for a man but guaranteed a woman's pleasure. The sonnet ends with an invocation the poet makes: he wants to enjoy the fair youth love and leaves his love to women. 

The speaking voice is addressed to a man who is so handsome that both women and men are amazed by him. Beauty isn't the only quality of this person, as a matter of fact he has got a woman's gentle heart but not acquainted with shifting change (lines 3-4), and his eyes are more bright then theirs. the fair youth is a man because at first Nature created a woman, so handsome that she was falling in love with her, but the nature who is a female subject can’t love another female subject, so Nature decided to turn this wonderful woman into a man. So women will love this man for their pleasure, but Shakespeare will love him only for love.

In this sonnet we find two big semantic fields: body and feelings. The words that recall us to the body are: face, hand, heart, eye and eyes. The semantic field of the feelings is formed by the words: passion, gentle, false, bright, gazeth, amazeth, pleasure and love. In this sonnet we find the themes of love, beauty and passion. Real beauty should assemble both men and women characteristics.

Probably Shakespeare wrote this sonnet because he wanted to say that we aren't only male or females but we have got something masculine and something feminine in our body and in our behaviors.