Yes - 1920 was the last year they only used the deep cut obverse portrait, which 'sucked' metal away from Britannia, and caused a 'ghost' of the portrait outline which you can see clearly in the top example; it's more common to see between 1911 and 1920 than fully struck up reverses.
In 1921 about half the pennies use a shallower portrait which partly alleviated the problem, but it wasn't until the Modified Effigy from 1926 that they reduced the effect to small enough not to worry about.