Visual representations are being used in typical sales meetings of the machine industry to exchange information and support social interactions. In these meetings, sales representatives design for granularity by taking into account verbal and visual details of communication. Our article builds on increasingly occurring collocated interactions in sales meetings investigating the social relevance of mobile devices in face-to-face settings. The article aims to understand the supporting and disturbing role of visual granularity in sales meetings and develops design implications for interaction designers. We conducted an ethnographic study of sales meetings in material handling and paper machine industries, including Conversation Analysis (CA) of video recordings, and involving groups of professional analysts that are seldom used in HCI. Our findings draw evidence from sales meetings and design processes on successful and unsuccessful use of granularity in visual representations. Finally, we propose seven design guidelines for visual granularity striving to understand buyers' perceptions and visual qualities.