Let’s start by recalling that meter is a structured way to organize music over time. Usually when we’re talking about meter we’re referring to how the beat is subdivided in a piece of music. For instance, if a song has one strong beat followed by one weak beat then the meter would be duple. If that same song subdivided the beats into 2 or 4 notes then we’d call it simple duple. Here’s a chart that might come in handy
|Duple||2 beats, subdivided by 2||2 beats, subdivided by 3|
|Triple||3 beats, subdivided by 2||3 beats, subdivided by 3|
|Quadruple||4 beats, subdivided by 2||3 beats subdivided by 3|
Just like how meter looks at how to group multiple beats together, macro-meter considers rhythmic changes over multiple measures. In Debussy’s work, Pagodes, you can see his attention to macro meter through the ever changing phrase lengths. The rhythm of the low “gong-like” notes are used to differentiate between sections. Notice that the low notes predictably happen every other measure at first, but then give way to more irregular lengths of four measures, one measure, and even some lengths that are outside of the written meter (6 beats, 14 beats, etc).
When listening for the macro-meter in Pagodes, it becomes clear that Debussy uses it as a compositional device. The structure of the entire work could be mapped to those low “gong” notes and it would follow a recognizable pattern.
This paper by Syliva Parker does an excellent job detailing in length how Debussy’s compositional style in Pagodes was influenced by Balinese Gamelan: https://symposium.music.org/index.php/52/item/22-claude-debussys-gamelan