Rocky: You got the technique. I must say it took a few shots but I felt that the town of Big Fork was just exploding with flowers (every where).
Cyn: The colors were just begging me, I felt, to photograph the petunias. This little town is sort of like one giant galleria with several unique art mini-galleries. I gave up lunch in the "Tea Garden", with my family ladies, to stroll the 3 blocks of Big Fork.
PapaJon et al: The technique used as Rocky cleverly pointed out requires a zoom lens. The zoom is quickly moved from, in this case, a telephoto setting to a wider setting. Shot in aperture priority. Takes a wee-bit -of practice but can be effective. However, 20-30 years ago, there was just too much of a good thing (like turning the camera diagonally is today IMO) spoiled the effect. Practice it as it is a terrific app by the photographer. It will most likely be quite awhile before I use it again or publish it.