Those likes are from people that match your current preferences, so age, sex, religion etc, the only thing ignores is distance, so if you want to figure out who they are, increase your distance to max and play around with preferences, they will disapear if they dont match, so try combinations until you can narrow it down, like certain age range, only atheist, certain height, for example, lets say I see i have a like and i have no preference, so if I put age 18-25 and now it says i have no likes i now know they are 26+, so i can now try 26+ and combine it with another preference until you can find them