Yes, it's normal.
So the Linx 8 has a 32GB storage drive, which in Windows terms is 29.8GB (To a storage drive maker they use a base of 1000, whereas OS's use 1024).
Of this 29.8GB, some of it gets removed (in reality its just hidden from the user) to store the full recovery image. This means you can always restore to this image and it never gets altered. The stock Linx image is actually quite large as it also includes Microsoft Office (over 1GB extra there) so this takes up almost 5GB. That 32GB is now down to 24GB and you've not even got to the installed part!
WIMBoot is quite clever, and that it uses the recovery partition to load most of the Windows system files. However, as you're probably aware, Windows likes lots of updates. And when a file gets updated it renders the one stored in the recovery partition obsolete. You eventually get two of the same file stored on that 32GB drive. One fixed in the recovery partition, and then the newer one actually stored on the part of the drive you can see.
The older the base recovery file is, the more space you'll lose as a result of the recovery partition files being out of date. Out of the box, you're generally left with around 19GB of usable space.
Linx 8 Owner