If your listing's data is displaying on Zillow, but the photos are not, it is very likely that the photos are too small for Zillow to display. Zillow has a minimum size requirement of 330 x 220 pixels. If a photo is smaller than that, Zillow cannot display it along with the rest of the listing information.
If one of your listings is affected by this, you would need to upload new, larger photos to the listing in Matrix. Once photos are saved in Matrix, they become available to downstream syndication sites, including Zillow, through our RETS server. Zillow should pick the new photos up in their next refresh cycle and then they should appear (as long as they are larger than 330x220).