call this script from terminal an pass to it the file with the URLs you want to download. One URL per line

downloadImgsFromJson.sh

#!/bin/bash

if [ $# -eq 0 ];then
echo "Usage:"
echo " downloadImgsFromJson.sh /path/to/json/file"
exit 1
fi

URLS=($(cat "$1" | grep -o "\"original\":.*$" | sed -E "s/\"original\": \"(.*)\"/\1/g" ))

for u in "${URLS[@]}"; do 
 	curl -O "$u"
 done