This is the 5756th most frequent Polish word.
wywołać
To cause, trigger, summon, or evoke.
In this sentence, 'wywołać' is used to describe the act of causing or provoking something—specifically reactions here.
Silne emocje mogą wywołać nieoczekiwane reakcje.
Strong emotions can provoke unexpected reactions.
Here, 'wywołać' refers to the process of developing film or photographs, connecting to the photographic context.
Postanowiłem wywołać zdjęcia z naszego ostatniego wyjazdu.
I decided to develop the photos from our last trip.
In this context, 'wywołać' is used to describe eliciting a response, such as a smile, demonstrating an influence on someone's feelings.