This is an illustration from chapter 24, volume 8, of Laurence Sterne's novel 'The Life and Opinions of Tristram Shandy, Gentleman' (1760-7). Tristram's uncle, Toby, is a veteran of the siege of Namur where he received a nasty groin injury. His hobby is re-enacting historic sieges in miniature in his garden, all of which he masterminds from his sentry box. Toby's neighbour, the widow Wadman, lays siege to his heart. She finally captures it by complaining that she has a speck of dust in her eye. Toby is forced to look, but sees nothing. But this eye, 'full of gentle salutations - and soft responses', seduces him and he falls in love. Leslie was a popular genre painter, modelling his work on that of Hogarth and Wilkie.