Was able to check but if you want to connect a gallery field with all of the information set up in the content manager, you would choose to connect to the gallery field . This connects to the gallery inside the line item; you should see inside the Connect a dataset section.
There is the option to connect a gallery using the default dataset option in which you connect the image, title text individually. Technically you have multiple fields in this setup and then are displaying them together in the gallery.