In Stave 1, the reader is given several clues that speak to the differences between Ebeneezer Scrooge and Bob Cratchitt. The first is their respective attitudes toward Christmas. When Scrooges' nephew addresses Scrooge at the last in his stirring speech, Scrooge is incensed while Bob Cratchitt can't keep himself from applauding the sentiment. Following this exchange, Cratchitt happily exchanges season's greetings with him as he is leaving, a concept that Dickens makes clear Scrooge has no interest in whatsoever.
The second deals with the two character's stations in life. When the two part at the conclusion of the work day, Dickens pointedly writes that Scrooge buttoned "his great-coat to the chin," and contrasted this fact to his clerk, who "boasted no great-coat." The fact that Scrooge had a great-coat to ward off the bitter cold shows that he had the financial means to purchase one while his clerk, Bob, did not.
The contrast continues when they leave for their respective destinations. Bob Cratchitt, ill-dressed for the weather, nonetheless went on his way merrily, playfully celebrating as he went. His destination, Camden Town, was the cheapest area to live at the time. Scrooge, after dining alone, went home to an enormous home, complete with ornamental fixtures.
These contrasts leave the impression of a poor, long-suffering employee whom the reader can immediately - if not relate to - feel empathy for.