Technically you are tracing Line of Sight from the Enchantment Transfusion card, not the creature it is attached to. It is a fine detail that doesn't really matter, since they are both invariably in the same place, but it is the Enchantment Transfusion that is doing the moving and not the creature.
I can see how the text you mentioned can be confusing, but I don't think it needs to be changed. It is saying that the Enchantment Transfusion is moving the other enchantments, and that the Enchantment Transfusion must check for legality before moving them in the exact same manner as you would check for legality whenever you cast them initially.