How to iterate over an array in an object with async pipe

try this :

<li *ngFor="let image of (album$ | async)?.images">
 <h1>{{ image }}</h1>
</li>

This should work for you with safe navigation operator

<li *ngFor="let image of (album$ | async)?.images ">
  <h1>  {{ image }} </h1>
</li>