The chapter begins with Winston feeling ‘gelatinous’ ….
” His body seemed to have not only the weakness of a jelly, but its translucency. He felt that if he held up his hand he would be able to see the light through it.”
The importance of this seemingly simple allusion is deeper than one would catch on first reading.
Winston had exposed his soul completely to O’Brien. Winston, who had spent his life keeping everything inside, being silent and trying to fade into the background, had opened himself to O’Brien.
He had exposed his relationship to Julia, exposed his hatred for The Party, agreed to do anything to destroy it and revealed his secret flat about the shop.
Subconsciously he realises what he has done, which is why he feels ‘gelatinous’ yet, consciously, has not appreciated his action.