Greetings Alexey,
That would do it. Whenever we do not see a kernel/ramdisk with an image file, we assume it is a whole disk image, and as a result, we don't partition, we only write out what we've been provided. This is rooted in the image convention storage with Glance, because you need a kernel/ramdisk to boot a partition, but you can "just boot" a whole disk image.
The disk utilities, in this specific case when you look at the disk, it thinks it is looking at a partition image on a loopback due to the lack of the partition table.
That being said, whole disk images are the preferred path given you have greater flexibility in the partition/structure/layout of the deployed host.
Hope that helps explain and provides the extra context.
-Julia