What is Higgins' attitude toward Eliza's feelings in Act IV?

Act IV begins to illustrate a change in Higgins' attitude towards Eliza. When Pickering, Higgins, and Eliza return to the Wimpole Street laboratory after the party, both Higgins and Pickering proceed to freely discuss the night's happenings.

While Pickering admits that he was nervous during the evening, Higgins maintains that he became immediately bored when he realized that they were going to win the bet. Higgins then continues to speak insensitively about how weary he became of training Eliza after the newness of teaching phonetics to a novice wore off. Meanwhile, Pickering insists that the venture was well worth the time and effort; as both continue to discuss their thoughts about the evening, neither Higgins nor Pickering bothers to acknowledge Eliza's presence in the room.

Meanwhile, Eliza has brought Higgins' slippers to him, but he hardly notices her efforts to make him comfortable. Greatly offended, Eliza eventually throws the slippers at Higgins, and this prompts a measure of corresponding anger from the man. Eliza accuses Higgins of having no more consideration for her than he does for his inanimate slippers. She thinks he is self-absorbed and callous in his disregard of her and demands to know what will happen to her now that she has won his bet for him.

Meanwhile, Higgins refuses to acknowledge Eliza's efforts; he angrily maintains that it was he who had won the bet, and he accuses Eliza of being presumptuous. Higgins' attitude towards Eliza is one of paternal concern; he thinks that she is emotionally overwrought by the whole affair and that she just needs to sleep her anxiety away. However, Eliza finds his attitude patronizing and she continues to press Higgins for more details about her future. Insensitively, Higgins suggests that Eliza might marry or even open her own florist's shop.

The exchange ends on an emotional note. Eliza angrily returns the ring Higgins had given to her in happier moments, while Higgins accuses his protege of being a 'heartless guttersnipe' who is ungrateful for all he has done for her. So, you can see that Higgins' attitude towards Eliza evolves from initial incredulity at her offended feelings to actual distaste and mortification at her sullen anger.