When copying a link from your public dropbox, it looks like this:
https://www.dropbox.com/s/utws2mjfpgcoo ... t.png?dl=0
Clicking that link will take you to the dropbox download page ....
but if you change the last 0 to a 1:
https://www.dropbox.com/s/utws2mjfpgcoo ... t.png?dl=1
it becomes an instant download