Starting in 2012, the Psychometric Society has published a Proceedings volume in tandem with the Annual Meeting. Society members can access these volumes by logging in via the button at the top of the page, then navigating via the small drop-down menu that appears on the right.
Millsap, R.E., van der Ark, L.A., Bolt, D.M., & Woods, C.M. (Eds.) (2013). New Developments in Quantitative Psychology. New York: Springer. ISBN 978-1-4614-9348-8.
A variety of IMPS (and other) photos exist in various places on the website. Here is a summary:
Annual Meetings of the Psychometric Society have been held since 1935. The meeting has come to be called International Meeting of the Psychometric Society (IMPS). The meetings have been held in many countries, including the United States, China, Canada, the Netherlands, Germany, England, Japan, Chile, Italy, and Hong Kong, and are usually in June or July. Attendees and presenters typically come from about 30 different countries.