In George Bernard Shaw's Pygmalion, how does Henry treat Eliza after the party and when she gives him his slippers?

After the party, Henry, Pickering, and Eliza return to the Wimpole Street laboratory. At this point, everyone is tired and ready to call it a night. Nevertheless, Henry and Pickering carry on a lively conversation about not leaving their coats and jackets carelessly strewn about the drawing-room. Pickering then asks Higgins whether they have any mail, and Henry, in turn, wonders aloud where his slippers are. Meanwhile, Eliza, the star of the evening, is ignored by both Henry and Pickering.

As Pickering brings the letter-box to Henry, Eliza retrieves Henry's slippers and sets them before the oblivious Henry. In due time, Henry notices the slippers and thinks that they have been there the whole time. Then, both Henry and Pickering commence talking about Eliza and her performance at the party as if she isn't in the room. This rude behavior is obviously insulting and insensitive to Eliza, but both men seem indifferent to her growing discomfort. The last straw comes when Pickering congratulates Henry on his achievement, without a word to Eliza.

In fact, Henry's only words to Eliza since their return home is in the form of an order: he tells Eliza to turn out the lights and to tell Mrs. Pearce to make tea, rather than coffee for him in the morning. At this point, Eliza becomes so angry that she can hold it in no longer. Then begins one of the most memorable conversations between Eliza and Henry in the play, where Eliza tells her benefactor exactly what she thinks of him.