I've used transform tools (floor, railings) for the end of bridge . The butterfly with Gaussian blur and motion blur at low opacity. The rest is obvious.
Edit2: Butterfly shadow.
As I see it now.Light source is from the left and low, 4 o'clock direction.
Adjustments of position, size, tone, saturation and opacity.It is not easy. (5 years and 1630 days ago)