We are first introduced to Tom Buchanan as Nick comments on his enormous wealth, 'various physical accomplishments' , and that he was a 'national figure in a way'. What stands out about this first introduction is the first thing Nick comments on is his 'various physical accomplishments'; the use of the word 'physical' gives the impression that Tom is a man who is fit and very physical. Furthermore, his 'various' achievements doesn't clarify what they are so they could be anything, they obviously boast his strength and maybe even a small hint at the fact that he could be responsible for physical violence.
The 'physical accomplishments' of Tom Buchanan is once again confirmed when Nick describes him; he uses words such as 'dominance' and 'aggressively' which all imply that Tom is once again a very 'physical', muscular body, a body that is 'capable of enormous leverage'. A 'cruel body' such as the one belonging to Tom Buchanan can and will set off warning bells in the head of the reader, a 'cruel body' that is capable of 'enormous leverage' cause's worry, wondering if that particular phrase is a clue or a foreshadow of something to come.
The feeling of contempt towards Tom Buchanan is not surprising because just from his description of muscles bulging over riding boots and 'muscles shifting' under his 'thin', 'effeminate' riding clothes, we can tell that the man is a very physical, more physical than mental. The bodily image of Tom adds to the 'physical accomplishments' that he has conquered and due to his 'hulking' body and manner its much more believable that he could be responsible of violence.
Additionally, when Daisy mentions her bruised small finger, with a 'black and blue' knuckle and then continues to accuse Tom of hurting it, the worries of Tom being able to hurt people becomes much more real and meaningful; he hurt his wife and