If you want to create a new image gallery for the Floor plan category images, follow these steps:

1. Create a new activity with "listing gallery" type, go to the WPL menu -> Activity Manager

Here you should select the "Position" button to choose where you want to see your gallery, for example "pshow_position3" or "pshow_position2". 

Also select the "floorplan" category of the images.  Here, you can change other options, like title, layout, size of the image gallery as well.

2. In the next step, you need to add some images in the property wizard and choose the floorplan category for them. Go to the WPL menu -> Add listing or Listing manager -> Edit property > Select Files to Load Images > Select Image Category > Select "Finalize" to Save.

Now you can see your new image gallery on the property details page.