The Experience Sampling Method (ESM) enables researchers to capture information about participants' experiences in the moment. Adding an end-of-day retrospective survey also allows participants to elaborate on those experiences. Although the use of photos in retrospective interviews and surveys for memory elicitation is well known, little research has investigated the use of photos in ESM studies. As smartphone adoption increases facilitating ESM studies and making photo sharing easier, researchers need to continuously evaluate the method and investigate the role of photos in such studies. We conducted a large-scale ESM and retrospective survey study via Android smartphones with more than 1,000 US participants, and analyzed participants' photo submissions, including how photo use correlated with participants' data quality and what, if any, value photos added for researchers. Our study sheds light on the role of photos in ESM and retrospective studies that researchers can reference when constructing future study designs.