Hi Mads,
Welcome to the community!
I've had a look at the recording, thank you for sending this. What I could see is that your freelancer is experiencing a known error where images cannot be added to lists in the rich text field.
We have discussed this at greater length in the following thread:
The solution for now is to make sure the image isn't added inside the list, but to make sure it's added between list items instead. Even better would be to use slices and model it as so:
[Rich text]
[Image]
[Rich text]