The global pandemic caused by the coronavirus disease (COVID-19) changes the lives of many people all over the world. In the context of stationary retail, a strong change of customer behavior occurs as mandatory safety measures like wearing facemasks and distance regulations have come into place. The sales personnel’s ability to understand and react to customers’ emotions is critical for service interactions and the customers’ overall satisfaction. Unfortunately, facemasks make it difficult to recognize other’s emotions and may lead to misinterpretation and confusion. To address this problem, this paper proposes the design of self-assessment interfaces that offer the customer an easy way to enter their emotions. As part of a Design Science Research (DSR) project, we designed three interfaces and evaluated them over the course of a design cycle. The results indicate that it is possible to use self-assessment technology in stationary retail to measure customer emotions.