Apple Mail email count discrepancy with Gmail webmail

Discrepancy between Apple Mail and gmail webmail

I'm looking at an email folder in my gmail account on both the webmail and Apple Mail. 1981 emails in the folder in Apple Mail and 1987 emails with the label on webmail. What explains this discrepancy? How can I identify those six emails without manually looking at every single one? 

I want to know this because I'm trying to move my emails to another account and I want to be sure I don't miss any.