The textbook context distinguishes between different types of workers: self-employed, casual wage labourers, and regular salaried employees. In the provided list, the owner of a saloon, cobbler, tuition master, and transport operator are considered self-employed, while the construction worker is a casual wage labourer. These categories typically fall under the informal sector where job security is low. However, a cashier in a cooperative society is comparable to the 'Cashier in State Bank of India' mentioned in the context, classifying them as a regular salaried employee working in the formal sector with job security. Thus, the cashier is the odd one out as they are a regular salaried employee, whereas the others are self-employed or casual workers in the informal sector.