The product is primarily labelled as Seed Tapioca as it contains tapioca which is declared in the ingredient listing. Sago is labelled as a reference due to the fact that although they are different, sago and tapioca may be used interchangeably in many recipes. 

In some parts of the world sago can be made from either sago or tapioca starch.  McKenzie’s has included sago in its labelling of Seed Tapioca for this reason so if you cannot find one for any reason, the other is a good substitute.