Proposed changes for the GTK Pinentry
A new pinentry shows up this way:

after clicking the button the content of the field is shown (not in this mock up):

If a letter has already been entered a warning is shown before a passphrase is revealed:

A new pinentry shows up this way:

after clicking the button the content of the field is shown (not in this mock up):

If a letter has already been entered a warning is shown before a passphrase is revealed:
