yup, they've formed corner reflectors both on the tip tank tails as well as the aircraft tail itself... tip tanks sides also don't look like they're chined so there would be surface specular scatter from the tank sides, as well as creeping wave diffraction from waves which travel around the tank circumference (tho I'ld expect they'ld use RAM to attenuate those surface travelling wave effects, but still a chine would have caused the wave to shed on the opposite side of the tank instead of creeping back to this side)...