thumbnail spoiler issue

so like everytime I watch an anime here on the thumbnail (or whatever you wanna call it) there's always a little picture of the episode so like for example lets say I'm watching a fight between 2 individuals and I have no idea who's gonna win then the episode ends and i go to watch the next episode just to find the dude laying down dead infront of the other dude he was fighting because it took a scene from the episode so thats pretty annoying and I was hoping it could like hey fixed maybe put a black picture instead or the first picture or like the anime's original poster. that's all thanks.