The book contains a few line drawings, that 'illustrate' the impossibility of describing intimate relations between people - but the illustrations' crudity seem to make such acts ridiculous (it may be this is the intent!)
The most interests section of the novel, for me, concerns G's stay inDomodossola at the time of the first flight over the alps, but here Berger subverts the story of the historical flight: at the time of the landing, G takes advantage of everyone's attention being elsewhere to seduce a hotel maid. The section of the novel set in England, where G apparently wakens to his (inappropriate) desires, is particularly evocative, but ultimately appears to lead nowhere.
There is no denying the intellectual and subversive prowess of Berger, but I found this novel stretched my patience. If you intend to read it, I highly recommend a companion read - C. By Tom McCarthy (short listed in 2011). Though C similarly has a rather unsatisfying narrative, it sparkles as a critique of G.