Hello, I think this was a misunderstanding at that time, the progress bar on an encrypted folder shows the percentage of the data present in the disk image in comparison to the capacity of the disk image. If the disk image capacity is 10GB and you have 1GB in the protected folder, then the "progress bar" will be at around 10%.
Note that the disk image capacity and size are two different things, the capacity is the size util which the disk image can "grow" but the size will be similar, just a bit larger, then the total amount of data present in the disk image.
I hope this helps,
Zsolt