How to track light box with <IMG> tracking pixel


I have come across on your community here on how to install. But what is missing is how to view on Analytic, especially on facebook.

Typically Facebook img pixel is tracking pageview.

img src=“{your-pixel-id-goes-here}&amp;ev=PageView” height=“1” width=“1” style=“display:none”/

My question is, how then can I differentiate a typical PageView triggers to what is fired by pixel so I can isolate and view it on Facebook Analytic? Any advise?