Change friends or don't put things in your phone everyone can't see. Or control who looks in your phone. 😎
Sounds like someone is seeing a certain someone and doesn't want another certain someone to see the first certain someone. 😱
Oh, what tangled lies.... er... lives we lead. 😀
Or certain photos, should they be seen by someone else, might prove embarrassing. Too many young ladies with rather large... accoutrements.. showing? 😛
I believe you might try BigBoss's BossPaper app. You can choose which photo set shows up with, if I recall, a respring. Not sure how well it is working on i4 4+, though.