When you see a lot of six packs in pictures they look like they do as the person showing them knows how to pose them also, being able to draw the centre line of your stomach in while tensing your abs makes them stand out more. They look a lot different when standing relaxed.
That... and many bodybuilding magazines use Photoshop a lot...
Anatomically, you might not even have the cuts or muscle separation in the lower Abs. Because at 7.6% you would see them. I got down to 7% and I had a 7 pack, that last one was just smooth no separation at all! Not everyone is going to have perfectly squared Abs.
So I think a strong 4 pack with the next 2 peaking out is the best you're gonna get. But you've done GREAT to get that!
Shift your focus now on building up the other muscles and maintain the Abs you got.