@julian thanks a lot! And for the second question, is there any way to do it?
EDIT (just to clarify, in order to be helpfull for anyone in the future): Since my image, didn't had the data-state="unloaded" (in fact id didn't have the data-state at all on the img tag) i had to first, use
posts.unloadImages(post); an then posts.loadImages(); to get the image loaded. That's because posts.loadImages() only searches for data-state="unloaded", posts.unloadImages. gets all images in the post provided without the class .not-reponsive and puts the data-state="unloaded" in each img tag.