This shot used a slow aperture to allow for a depth of field generous enough to include both the subject in the picture and the background behind them, and to also allow (even require) the use of a slow shutter speed that provided the dynamic effect of motion seen in the birds that enhances the intensity of stillness seen in the invitation/hesitation interaction evident between the boy and the swan, the focal point of which falls in line with the three thirds rule. Thanks to rpe35mm for their comments.
great shot, I remember when I was about 9 years old I tried to feed a swan and it chased me a bite me on the behind. I still can't get that close to them.