However when I link them to my Itch.io pages, there is more stuff added. I do not even know where these files come from.
Could you elaborate on this? Are you referring to Youtube showing recommended videos and such after a video ends?
Viewing post in Question about Youtube
Sorry not to explain better.
What happens is this. My video will play in it's entirety. But when the video finishes a random picture pops up.
I do not even know where the picture comes from. There was a picture of a rock, a picture of what looks like a battle, a picture of grass, etc, etc. It varies each time.
I just don't want them, because it looks so unprofessional.
Do those pictures appear in your video before you uploaded it on YouTube?
If the answer is no, then what you are seeing is most likely YouTube’s recommended videos and such, which are based on your profile, so every user will see something different. To me knowledge there’s no way of removing those.