Response policies for the notes page.

Card F
Content-Security-Policy: frame-ancestors 'self'
Meaning on this card: a parent may embed the page only when the parent is the same origin.
An untrusted parent is not on the list.

Card C
style color: green
Meaning on this card: the text color changes. Embedding is untouched.

frame-src would name where this page may load frames from.
frame-ancestors names who may embed this page.
MDN describes that difference. The directive checks ancestors.