Help with passing variables to partials

[kylef-fotf]

Hello, I am trying to pass an asset url to a component which will make a glide call.

This component works in other templates where the entry has an image asset that is passed into the partial.
However, in one template, the image background is set with a string, and I cannot get it to pass to work with the partial.

Below is the section of the template trying to set the image_url variable to pass it to the partial.
Echoing image_url on it's own will correctly output the string, but passing image_url into :image just gives an empty string.

{{ if type == 'conference' }}
  {{ image_url = "/img/Events-Pg_hero_Conferences.jpg" }}
{{ elseif type == 'retreat' }}
  {{ image_url = "/img/Events-Pg_hero_All-In.jpg" }}
{{ else }}
  {{ image_url = "/img/Events-Pg_hero_Retreats.jpg" }}
{{ /if }}
{{ partial:components/background-image :image='image_url' class='event-cover bg-t-c border-gold' }}
  <div class="container">
        [...]
  </div>
{{ /partial:components/background-image }}

The background-image partial looks like this:

<div class="{{ class }}" style="
    background-image: 
        url('{{ glide :src='image' preset='2xl'}}');
    background-image: 
      -webkit-image-set( 
        url('{{ glide :src='image' preset='xl'}}') 1x, 
        url('{{ glide :src='image' preset='2xl'}}') 2x
      );
    background-image: 
      image-set( 
        url('{{ glide :src='image' preset='xl'}}') 1x, 
        url('{{ glide :src='image' preset='2xl'}}') 2x
      );
">
    {{ slot }}
</div>

This outputs like:

<div class="event-cover bg-t-c border-gold" style="
    background-image: 
        url('');
    background-image: 
      -webkit-image-set( 
        url('') 1x, 
        url('') 2x
      );
    background-image: 
      image-set( 
        url('') 1x, 
        url('') 2x
      );
">
    <div class="container">
    [...]
    </div>
</div>

What am I doing wrong?