The RO profile in Bru'n Water represents a typical product water from a home RO unit that has its feed water pre-softened with an ion-exchange water softener (salt water). This arrangement is a typical recommendation for home RO installation in areas with high hardness in order to reduce membrane fouling. That is one reason why the sodium content is a little higher, but even if the feed water was a typical hard water, the sodium content may still be slightly high since the monovalent sodium ions can pass more easily through the membrane.
The Ca and Mg content can be considered typical, the Na content is probably slightly higher than typical, but then you're only talking about a difference of 2 or 3 ppm.
The RO profile is included in Bru'n Water to illustrate that RO water is not ion free, but it has very low ionic content.