Hello!
Thank you for telling me about your difficulties with the game. The quest #15 called "Hidden Images" was given a difficulty that was far too high. I'm sorry about that. I would even say that hidden images in general are very difficult to find. ^^'
But anyway. Here is the list of the (approximative) positions of the images;
Hero's house (in) : /2
Hero's house (out) : /3
Red Forest : /3
Eleanor's house (in) : /3
Maria's house (in) : /3
Erina's house (in) : /6
In addition, I've posted the exact position of 10 images on Discord.
Good luck on IMAPIAW! :)