Why is not is_page working once I put it within the features.php file?

I’ve web page known as “Apple”, the web page’s ID id 2533.

In web page.php file I’ve line:

echo $bannerimg 

And this perform in features.php:

if ( is_page( '2533' ) ) {    
    // additionally examined with 'Apple'
    $bannerimg = 'apple.jpg';

} elseif ( is_page( 'take a look at' ) ) {    
    $bannerimg = 'take a look at.jpg';

} elseif ( is_page( 'admissions' ) ) { 
    $bannerimg = 'admissions.jpg';

} else { 
    $bannerimg = 'residence.jpg';
}  

The purpose is the $bannerimg echoes “residence.jpg” on each web page, together with Apple, take a look at and admissions.

I’ve even checked all of the IDs utilizing the_ID & $page->ID. Nothing. So I suppose there’s one thing unsuitable with the code above?