The correct answer to this open question is the following.
Thomas Rowlandson's portrayal of eighteenth-century society was different from Lemonnier's in the following way.
French artist Anicet-Charles Limmonier depicts the scene of aristocratic people at the Mari Rodette Geoffrin's saloon. These aristocratic people are paying attention to the lecture of famous Enlightenment thinker Voltaire. The painting is very colorful and we can see the elegant apparel of the aristocrats.
On the other hand, the portrayal of the famous British cartoonist Thomas Rowlandson's portraits middle-class people in a totally different environment: a middle-class Caffe, in Salisbury Marketplace. The environment is more relaxed, and patrons are reading newspapers and having light conversations.
In the times of the Enlightenment, people used to meet at coffee shops or saloons to talk about the issues of the time.