I've prepared a PowerPoint project and each slide contains a picture. I didn't use any filters, but the pictures are changed as if I've used effects on them. How can I stop the app from doing this? Example
That looks like two totally different pictures, power point does not change pictures unless you used the wrong aspect ration and it extends or squishes it or have some other option there during import. There is nothing in PPT that by default modifies pictures you add.