How does Higgins treat Eliza in Pygmalion?

Professor
Higgins objectifies Eliza as the main component of his experiment, even bullying her at
times.

When Eliza takes a taxi and comes to Higgins for speech lessons so
that she can "be a lady in a flower shop stead of sellin at the corner of Tottenham Court
Road," (Act II) Higgins speaks about her to Pickering as though she is not a real
person. 

HIGGINS. Pickering, shall we ask this baggage to
sit down, or shall we throw her out of the window? (Act II)

After saying things that hurt Eliza's feelings because he speaks of her as a mere
object, such as his proposal to Pickering that he can make a "duchess out of a
guttersnipe," Higgins calls her ungrateful. Even when Pickering scolds his friend, asking
him if he does not think the girl has feelings, Higgins callously replies, 

HIGGINS. Oh, no. I don't think so. Not any feeling that we need
bother about. (Act II)

Having thus dismissed Eliza's
feelings, Higgins returns to concentrating on what he considers essential; namely, her grammar
is atrocious and will be harder to correct than her pronunciation.

So often,
he is guilty of this domineering superiority. Throughout the later acts, when Eliza becomes
angry after he has gone too far with his impetuous bullying, Higgins employs coaxing cleverness
rather than an apology to subdue her. It is only when Eliza takes a stand for her own dignity
after the ambassador's party that Higgins begins to perceive Eliza no longer as a sort of
millstone around his neck, but as a person who is deserving of his
admiration.