Clarification on understanding Linux disk usage with df and how tmpfs should be assessed
tmpfs filesystems are RAM disks and have nothing to do with your storage media.
In the second scenario, your 200GB disk contains a 39GB root filesystem, a 200MB boot filesystem, possibly swap space of unknown size and probably a large amont of free space.
To see swap space, run swapon -s. To see free space, use a partitioning tool like fdisk -l or parted /dev/sda print.
You don't seem to be using filesystems on LVM volumes or network storage. They would be listed by df.