Personally, I don't check on my visitors as I'm not here looking for meetups, so it's not anything I'm interested in knowing about.

I do sometimes make visits to profiles to get an angle on someone's personality, and may go back a second time if I need to remind myself, but mostly it's because I tapped on the wrong part of the screen and ended up visiting some random person.

I think it is just your personal list of stalkers.
Only guessing, but I assume it is people who have viewed your profile.
You must have sparked our interest.

It's the fun part of the site...you get to decide if they are stalkers or potential love interests...kidding...just people interested in who you are based probably on something you posted or your lovely picture. Like any dating site, no etiquette required, unless you want to strike up a conversation with them, with something like, "saw you stopped by but didn't leave a message..."

I thin it jus tshows who looked at your profile