According to the rubric at the top of the first screenshot, I had completed the level requirements with 1 move left.
Despite this, I did not automatically advance to the next level. I spelled the word "papa" next using the crown on the "p" in the upper right corner, and then I got the level failed screen, which stated that I needed two more words. This is the second time this has happened, hence why I decided to screenshot it.
Even if I was willing to use gold bars to complete this level, how would I know which word lengths to aim for?