The files of the file upload are avaiable at _files property instead of files. This should show the values.

  <ng-template pTemplate="content">
    <ul *ngIf="uploader.files">
      <li *ngFor="let file of uploader._files"> <!--  changed here! -->
        <img
          src="/assets/images/pdfimage.png"
        />
        {{ file.name }}
      </li>
    </ul>
  </ng-template>

Related Answers with Working Examples:

In the (onRemove) function of a p-fileUpload, is it possible to get a list of the remaining files?

https://stackoverflow.com/questions/79246000/in-the-onremove-function-of-a-p-fileupload-is-it-possible-to-get-a-list-of-th