It means we will identify any form field where users are spending a lot of time before typing something. It might mean that either the field name is confusing or they do not intend to give you that information so early in the flow. You can analyze the sessions and make a conclusion basis that.
Example: When you try to book an insurance, sometimes they ask you for phone number and email even without showing a list of policy or so. This makes a lot of users wonder and they spend a good amount of time thinking whether to give it or not. Maybe, the thing to do is to first build trust or first help before asking for personal details. Also, one time we tagged a sessions where someone wrote 'Name/Email' in the field name and a user tried to fill the field as 'firstname.lastname@example.org' after spending quite some time.