berryconv_gui.py changes source image

[amantotek]

$ sudo dcfldd if=/dev/sdb of=$(date +%Y%m%d)Xub20p04RPi3BplusHAL3.img
479744 blocks (14992Mb) written.
479744+0 records in
479744+0 records out
$ sudo sync
$ ls -alt *.img
-rw-r--r-- 1 root root 15720251392 Apr 27 16:42 20210427Xub20p04RPi3BplusHAL3.img
$ sudo dcfldd if=/dev/sdb vf=20210427Xub20p04RPi3BplusHAL3.img
Total: Match

$ sudo md5sum /dev/sdb 20210427Xub20p04RPi3BplusHAL3.img
185eb0ba37e247f08ded4a5aacd6b7c4  /dev/sdb
185eb0ba37e247f08ded4a5aacd6b7c4  20210427Xub20p04RPi3BplusHAL3.img

(Deploying berryconv_gui.py with source 20210427Xub20p04RPi3BplusHAL3.img)

$ ls -alt 20210427Xub20p04RPi3BplusHAL3_bb.img
-rw-r--r-- 1 root root 5159284736 Apr 27 18:08 20210427Xub20p04RPi3BplusHAL3_bb.img
$ md5sum 20210427Xub20p04RPi3BplusHAL3*.img
113b55dff49b0c9332ade62fa6efa4d3  20210427Xub20p04RPi3BplusHAL3_bb.img
592640bb29afa5e864e96e74b45245fe  20210427Xub20p04RPi3BplusHAL3.img
$ ls -alt 20210427Xub20p04RPi3BplusHAL3.img
-rw-r--r-- 1 root root 15720251392 Apr 27 19:10 20210427Xub20p04RPi3BplusHAL3.img

After using berryconv_gui.py the source length agrees but MD5SUM has changed.