The tools->close page has a list of questions with "Most Close Votes". This list is currently showing all questions in the list with exactly 1 close vote, even though several questions have 2 or 3, as you can see by the number next to the close button, and in the new close question review tool.
The page you are referring shows the votes received from the questions, in the period shown from the tab you are currently seeing. For example, if you are watching at the "today" tab (which is the default one), 1 means one vote received today; the question could have 3 votes casted the day before, and the "today" tab would still show 1.
Compare the following screenshots. I have taken them from Drupal Answers, but they show what happens here too.
The first screenshot shows the last question received one closing vote, while the other two screenshots show the same question received two closing votes. (It is the same question; I checked the links.)
If I then look at the question, I notice the following.
This means the question received three closing votes: one vote was casted in the past 7 days, one vote was casted in the past 14 days (but not in the past 7 days), and the third one was casted more than 30 days ago.