docs: remove lightbox gif from Use Directives to Watch the DOM sectio…

…n. (angular#42369)

This gif is out of date and causing reader confusion.

Fixes angular#40193

PR Close angular#42369

aio/content/guide/lifecycle-hooks.md

@@ -395,14 +395,7 @@ Here it is attached to the repeated hero `<div>`:
 
 <code-example path="lifecycle-hooks/src/app/spy.component.html" region="template" header="src/app/spy.component.html"></code-example>
 
-Each spy's creation and destruction marks the appearance and disappearance of the attached hero `<div>`
-with an entry in the *Hook Log* as seen here:
-
-<div class="lightbox">
-  <img src='generated/images/guide/lifecycle-hooks/spy-directive.gif' alt="Spy Directive">
-</div>
-
-Adding a hero results in a new hero `<div>`. The spy's `ngOnInit()` logs that event.
+Each spy's creation and destruction marks the appearance and disappearance of the attached hero `<div>` with an entry in the *Hook Log*. Adding a hero results in a new hero `<div>`. The spy's `ngOnInit()` logs that event.
 
 The *Reset* button clears the `heroes` list.
 Angular removes all hero `<div>` elements from the DOM and destroys their spy directives at the same time.