How does Tennesee Wiliams gradually reveal Tom's character by things he says or does or by how other characters relate to him.(Three specific scenes)

That Tom is dominated by his mother is obvious in the Scene 1 of "The Glass Menagerie."  It opens with his mother calling him to dinner, "We can't say grace until you come." Having come to the table, Tom is then criticized by Amanda for his eating habits.  Tom responds to all this criticism,

I haven't enjoyed one bit of this dinner because of your constant directions on how to eat it.  It's you that makes me rush through meals with your hawk-like attention to every bite I take."

There is obvious tension between him and his mother.  This tension increases in Scene 3 as before the stage is lighted, "the violent voices of TOM and AMANDA are heard."  When Tom curses, Amanda become very offended and calls Tom an "idiot."  He tells Amanda that he has nothing "in my life here that I can call my own!"  Amanda has taken a novel by D.H.Lawrence that Tom has been reading back to the library because she is offend by its contents.  Irate at her actions, Tom says that he is going out.  Amanda insists that he will listen to her.  Tom returns and tells her that he, too, is at the end of his patience.  He has been doing what she wants him to do.  Revealing that he is unhappy at his job, he tells his mother,

I'd rather somebody picked up a crowbar and battered out my brains--than go back mornings! I go. Every time you come in yelling that God damn ' Rise and Shine!' I say to myself, 'How lucky dead people are!'....Why listen, if self is what I thought of, Mother, I'd be where he is--GONE! [He points to his father's picture.]

In Scene 4, the tension between Tom and his mother increases after he stays out late.  The next morning his mother will not speak to him.  In the stage directions,

TOM glances sheepishly but sullenly at her averted figure and slumps at the table.

When Tom apologizes to his mother, she justifies her overbearing behavior because she has

had to put up a solitary battle all these years.  But you're my right-hand bower!  Don't fall down, don't fail!

Tom gently tells her that he does try. Amanda then tells Tom that Laura has cried and said that her brother is not happy in the apartment with them.  She urges him not to take after his father's ways.  Tom replies that he has much that he cannot "describe" to her, but he loves adventure and so he goes to the movies because he cannot get any excitement at the warehouse.  When Amanda resumes her querulous attitude toward him,Tom retaliates,

Man is by instinct a lover, a hunter, a fighter, and none of those instincts are given much play at the warehouse!

Amanda mentions that she has seen his letter from the Merchant Marine; she warns him against what he is dreaming of:  "But until that time you've got to look out for your sister."

Tom asks "What can I do about it?" and Amanda tells him to "overcome selfishness."  Tom gets up, grabs his coat, and says, "I'm too late to--"  However, when Amanda insists that Tom find a man at the warehouse who can call for his sister, Tom calls back, "YES!" as he leaves again.

Although Tom appears to be caring about his sister, the responsibilities of being the only man of the household and the dismal job he has are too much for him; he simply wants out of his confining situation.