In this paper two participatory design activities are described in which teenagers create lo-fi designs describing emotions and explain the rationale for their design choices. Designs annotating and describing emotions are categorised as anthropomorphic, abstract, object based, or biomorphic. The paper concludes that teenagers use a variety of visual metaphors to describe emotions, that teenagers use anthropomorphic visual metaphors the most to describe emotions and that teenagers make more use of abstract and biomorphic visual metaphors to describe ‘negative’ emotions. The effect of materials on designs is analysed, suggesting that teenagers are more likely to create designs describing emotions featuring anthropomorphic visual metaphors when using malleable three-dimensional materials. Suggestions are made for the use of externalisation and personification as part of interactive emotion displays within affective systems. This research will be of value to interaction designers and Child Computer Interaction researchers seeking to understand how teenagers use different visual metaphors to describe different emotions. The contribution of this work is a categorisation of the visual metaphors teenagers use to express different emotions.