By default, each custom data item only shows up to 2 dynamic fields worth of information. In order to see all of the dynamic fields and their associated values, click on the icon which then switches to icon.
The height of the custom data item will be expanded to expose more dynamic fields. If there are too many, a vertical scroll bar will appear allowing you to scroll through all of the dynamic fields.
To collapse the custom data item back to the default height, click on the icon.