The last one is an example of irony
It is a simile
The sentence is comparing the arms to helicopters blades using *like
Umm that’s hard to awnser
Gerald thinks that nothing much has really changed in his relationship with Sheila. Yet he's deluding himself. He may not have changed, alright, but things between him and Sheila most certainly have. Although genuinely moved by the death of Alice Renton (a.k.a. Eva Smith), he cannot emerge beneath the shadow of his domineering father. He knows that without his father's money he simply won't be able to make it on his own.
