That's the standard language on an Icelandair ticket and is consistent with the policy Arctifox linked to:

For some reason the personal item is never mentioned on the ticket. I guess FI doesn't consider a personal item to be baggage? Some Scandanavian airlines word it the same way but also allow a personal item.
Unfortunately if you do encounter an agent who uses the sizer, it's the 7.8" and 21.6" dimensions that get enforced, not the 45 LI total.