Can't really tell from your photos, but the Bestop bikini top should have some plastic flaps sewn into the sides, which tuck into the door surrounds. I don't see those in your photos. If you don't have those, you may have gotten the wrong top for your JK...mine has those plastic flaps, and some useless velcro straps that loop around the door surround, that I don't use. The plastic flaps keep it pretty tight by themselves. Also, mine didn't come with any loose straps.
07 Jeep Green 2 door Rubicon; OME Std suspension; 33" BFG KM2; Shrockworks stubby front, Expedition One rear bumpers, JKS adj trackbars f/r, Poly HD tie rod, Moog TRE on drag link.