Tom's Diner was originally an a capella album track by Suzanne Vega, before dance act DNA turned it into a club smash in the 90s. The lyrics are a vignette, with Vega sitting in a cafe reading a newspaper and observing the people around her.
The mundane subject matter seems like an odd fir for the singer who brought us "Work Bitch" and "Slave 4U" - but it turns out that Britney's limited, husky voice is a good match for Suzanne Vega's deadpan delivery. Although you have to suspend disbelief when she sings "I pour the milk". Britney has a team of people to do that for her.
I'm not so sold on the backing track, mind you. Maybe we can go back to the a capella?