If you have other photos that can be made your primary photo just click the button and the process to change it should begin. If none of your other photos are marked as “make primary” your current photos are not seen as good candidates for your primary photo.
This would normally be because they want your primary photo to be a clear headshot of only you.
On the left, you should see a section labeled Visibility Options. You can still contact people when your profile is hidden but they won’t be able to look at your profile so that sort of defeats the purpose (so remember to make yourself visible if you start contacting people).
To be clear though, I don’t believe there is a way to differentiate normal users from paying users normally.
Most people look at a large number of profile but contact very few (or sometimes none at all).
Don’t take it personally and if you think she’s interesting why not contact her? In my online dating guide I discuss this in great detail in my section on an absence of responses.
What Does It Mean If She Looked at My Profile but Didn’t Wink? Can I Hide My Profile But Still Quality for Guarantee?
Keep this in mind if for some reason you’re hiding your profile in an attempt to not let people know you were looking at them!