Why is my video thumbnail a cartoon/illustration?

Vimeo will auto-replace some thumbnails due to mature content settings on Vimeo. Please check this info to manage your mature content settings:

https://vimeo.zendesk.com/hc/en-us/articles/224818087-Content-ratings#:~:text=Content%20ratings%20are%20a%20way,next%20to%20their%20video%20title