.compose-form__publish-button-wrapper button {
  display: flex;
  background-color: #6d40c0;
}

.compose-form__publish-button-wrapper button::after {
  content:'aïe, aïe, aïe !'; 
  text-indent: 0;
  display: block;
  line-height: initial; /* New content takes up original line height */
}

a[href="/publish"]::after {
 content:'aïe, aïe, aïe !';
}