As public displays integrate 3D content, Overview+Detail (O+D) interfaces on mobile devices will allow for a personal 3D exploration of the public display. In this paper we study the properties of mobile-based interaction with O+D interfaces on 3D public displays. We evaluate three types of existing interaction techniques for the 3D translation of the Detail view: touchscreen input, mid-air movement of the mobile device (Mid-Air Phone) and midair movement of the hand around the device (Mid-Air Hand). In a first experiment, we compare the performance and user preference of these three types of techniques with previous training. In a second experiment, we study how well the two mid-air techniques perform with no training or human help to imitate usual conditions in public context. Results reveal that Mid-Air Phone and Hand perform best with training. However, without training or human help Mid-Air Phone is more intuitive and performs better on the first trial. Interestingly, on both experiments users preferred Mid-Air Hand. We conclude with a discussion on the use of mobile devices to interact with public O+D interfaces.