The photo may have been taken at an event celebrating Davis' flight on either STS-47 in 1992 or STS-60 in 1994. The banner in the background reads, "Jan Davis / A Golden Homecoming."
The float was made by Marshall Space Flight Center. Von Braun Research Hall can be seen in the background. The photo likely dates from the 1980s or early 1990s, when the NASA worm logo was still in use, as seen on the sides of the float.