This is another great use of expressive typography. Using the “o” instead of any other letter was the best choice with this word. The “o” in this case gives us the “aw” sound when saying the word “drop” rather than a long o sound like the word “stove”.
The meaning of the word "missing" is portrayed frm the absences of stem of the letter "i". By leaving the titles, it portrays that a part of the letter has been removed, reinforcing the meaning of "missing".