The reason is plain and simple, and even made most of the netizens who noticed this fact about Dahyun, LOL! Check it out below:
Do you realize how freakishly keen Dahyun's inner "camera detecting radar" is?
Netizens said, "Heol, this is surprising. How did she find them all?", "She must have 30/30 vision kekeke", "She would make one hell of a good sniper", "OMG when the cameraman tries to take photos of her in secret and she just waves like that, he'll probably jump from the scare kekekeke", "No but srsly how did she find them kekekeke", "It's like a cute horror movie kekekeke", "Isn't this what you call animalistic sight??", and more.
Watch out, 'Dispatch'!