The COVID-19 pandemic caused many scientific conferences to move online, posing a great challenge for scientific communication. This change offers potential advantages and disadvantages for inclusion, diversity, and scientific advancement. Here, we analyse participants’ experiences of the Why Study Mammographic Density? Conference to explore some of these issues and identify key points of contention between different stakeholders. We found that while increasing participant diversity is facilitated by online conferencing, if the participants cannot interact informally with each other, there is value which is lost. In returning to in-person conferences, it will be important not to “shut the door” on those whose participation was enabled by the online format.