Normally the tags view will get it's display parameters from either:
-- the currently clicked menu item, or
-- the FLEXIcontent tags cloud module link that the user clicked
In all other cases you will need to define a default a menu item to be used as default configuration of the tags view
- Create a menu item of type FLEXIcontent Tag
- At this menu item, set any other parameters that you may need, e.g. configure which image field should be used as item image, or set it to extract image from item's description
- At global configuration set the ID of this menu item as Default menu item for getting configuration of tags View, it is parameter:
Content Display / Tags view / Default Menu Itemid