How do I pass variable to media function in templates

[VarunAgw]

{{$selectIcon = "icons/select-" . $selectLogoSize . ".svg";}}
<img src="{media="{$selectIcon}"}" />

That's how my code looks like, but for some reason, second line doesn't work. But if I remove the variable and manually enter the path as static, it works. How do I fix it?

[VarunAgw]

Bump

[Sonya*]

Try this 

 

[VarunAgw]

Thank you @Sonya*