I really don't know how to put up a video, but you can go to this site to see a video of a chicken laying an egg. The view is from the business end of the hen.
When the egg is coming out, the egg tube descends and comes out first. This way, the egg never touches the outside opening where the poop comes down. The egg will not be contaminated by fecal matter. However, poop in the egg laying box might get on the egg. There is never poop on my hen's feathers. An internal problem that causes diarrhea or dirty laying conditions would make the egg poopy. Occasionally I do have a bit of poop on and egg. Usually that is when the chicken has tracked in poop on dirty feet during a rainy period or I have been remiss in turning or replacing the pine straw.
My hen's boxes are filled with pine straw. They rarely poop in their egg box. Their is so much pine straw that it can be turned and fluffed to keep the straw dry and fresh. Notice that the chicken is standing, not sitting.
It seems totally unnecessary to trim a chickens butt feathers. Mine have huge fluffy butts and the eggs are mostly perfectly clean. This trimming is a practice that just seems wrong.
This whole post is left-justified in draft, but it is centered once published.....grrr.
Okay, was that not jaw-dropping awesome? Have you ever seen a hen drop/lay an egg? Have your ever heard of trimming butt feathers???