When running the voucher report, make sure that you specify the number of pictures you want to show on the Itinerary Report.
1) Click on File > Reports > Itinerary.
2) Scroll down to the Supplier information tab and enter the Number of Supplier Pictures
Also go to the Service Information tab and do the same there, if applicable:
After doing the above, click OK to run your report and see the supplier (and service) pictures.