NIOD is currently showing 23% off selected items as the main deal, best for you if the products you want are included in that selection and you want a percentage saving across those items. The 23% off sale applies to specific products only and is not compatible with any other deals, so it is most useful when the items in your cart are participating in the sale.
Small baskets under CA$25: If your total is below CA$25 and the items you want are not part of the 23% off selection, you will not meet the free shipping threshold and you will not get the sale saving. For a CA$20 cart of non selected items, paying shipping will often add more than any small discount, so consider adding a low cost product that is in the CA$25 plus range or choosing a selected sale item instead.
Baskets of CA$25 to CA$34.99: Free shipping kicks in at CA$25, so if your cart is between CA$25 and CA$34.99 and contains non selected items, the free shipping offer is the clear benefit; it applies site wide and requires no code but cannot be used with other offers. If a selected item is in that cart and the 23% sale applies, compare the raw saving from 23% against the value of free shipping, because the sale cannot be combined with free shipping when the terms say offers are not compatible.
Baskets over CA$35 where the product is a participating sale item: Use the 23% off selected items. On a CA$100 order made up of sale selected items, the 23% discount reduces the total to CA$77, a saving of CA$23. That is likely bigger than free shipping alone. If some items are not in the sale, the 23% discount applies only to the selected items and cannot be combined with other offers.
Buying the Superoxide Dismutase 3 Enzyme Mist for CA$35: This product is listed at CA$35. If that item is not one of the selected products in the 23% sale, you still qualify for free shipping because the order is over CA$25. If the CA$35 mist is included in the selected items, the 23% saving would bring its price to CA$26.95, which is a saving of CA$8.05 on that product.
Buying the Fractionated Eye Contour Concentrate for CA$94: If that product is sold at CA$94 and is included in the 23% selected items, apply the 23% discount and you pay CA$72.38, saving CA$21.62. If it is sold as a separate deal and not in the selected sale, you pay the CA$94 price and still qualify for free shipping.
When choosing between these offers, take whichever option leaves you with the lower total for the same basket. If the items you want are explicitly listed in the 23% sale, that discount will usually beat free shipping for larger baskets; if they are not, free shipping on orders over CA$25 is the better pick. The terms say the 23% sale is not compatible with other deals, so do not expect to combine it with the free shipping offer when the site marks the offers as incompatible.