The Importance of being Earnest- Cigarette Case

When reading the text, I was not expecting for Algernon and Jack to be at a party like they were in the clip. I was expecting more of them getting ready for guest to come over and getting the house prepared for Lady Bracknell. The reason I personally did not see the party scene in the text was because the way Algernon was talking with Lane.

Algernon.  And, speaking of the science of Life, have you got the cucumber sandwiches cut for Lady Bracknell?

I was expecting Algernon and Jack to be sitting in the house on separate couches talking with one another. Instead they enter this huge party scene and sit on separate couches with women lighting their cigarettes for them.  I think they portrayed it in the movie like this to make it come off more comedic then serious like how I would suggest in the text. Then in the text, Lane brings the cigarette case in. In the movie Algernon pulls the cigarette case out of his jacket. Algernon then proceeds to ask him about the cigarette case as if it was the perfect moment being surrounded by people. Jack sounds annoyed in the clip perfectly, as if he is embarrassed and does not want to talk about it in front of people but just wants Algernon to give him the case and leave it at that. Then while Algernon is accusing him, I see Algernon say something that Jack was suppose to address according to the text. In the text Jack says,

Jack.  [Moving to sofa and kneeling upon it.]  My dear fellow, what on earth is there in that?  Some aunts are tall, some aunts are not tall.  That is a matter that surely an aunt may be allowed to decide for herself.  You seem to think that every aunt should be exactly like your aunt!  That is absurd!  For Heaven’s sake give me back my cigarette case.  [Follows Algernon round the room.]

but in the movie Algernon addresses the size comment and Jack says nothing about it beforehand. Which plays out well for the movie and the setting because it makes Jack seem like he is being ambushed with all these questions to try to make him slip up on a lie. In the text Jack seems like he is more trying to defend himself but in the movie he seems more relaxed and ready to come out with the truth. The last minutes of the clip when Jack finally says he is both Ernest and Jack, he is almost laughing at the confusion of Algernon and seems very relaxed which makes it seem a bit more comical.