When combining the tangible properties of Smart Textiles (such as the hand of the fabric) with the intangible properties from services (such as dynamic properties and business models) the result can be considered as a Smart Textile Service. Practitioners in a healthcare context are used to an embodied approach to examine and improve the bodily abilities of their clients, therefore developing the intangible components of Smart Textile Services for healthcare can introduce difficulties in a participatory design process. In this article we investigate how embodied interactions with the prototypes of service interfaces help to assess not only tangible but also intangible aspects of Smart Textile Services. The analysis concerns a design meeting that took place during the multistakeholder process to develop the smart cardigan and service “Vigour” for people with dementia. During this meeting the current state of the development of the Smart Textile Service is assessed by two physical therapists, a manager of the eldercare organisation and two designers. One of the main findings is that the validation of assessments takes place by relating the body to tangible objects, imagined tangible objects, imagined future tangible objects and imagined intangible objects. We argue that bodily behaviour provides the basis for participants to agree on favourable/non-favourable tangible and intangible aspects of a design.