News Flash!

I'd make a joke about how it must be one unbelievably slow news day in Snowdin but on the other hand, Undyne's a hero and major public figure, at least eighty percent of their news must be about her exploits ("Local Fish-Lady Tries To Nail Up a Picture, Breaks House and Creates New Neighborhood").

Also I firmly believe she posed specifically for that picture for the occasion. She didn't know what the article was about, it's just Undyne's instinct to pose dramatically at cameras.