Hey, only got back to you now because of being locked out. Qi Gong is quite dissimilar to yoga, as it is mostly focused on fluid movements and standing postures that are relatively easy, whereas yoga usually involves a lot of stretching and bending. The remarkable thing is that both increase flexibility, because in both you become conscious of your body and deeply relax core muscles. For a short demonstration you can see the following youtube clip, from the teacher of my teacher: