system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How do different images from the same camera vary in file size?

Wouldn't a camera with a constant resolution capture images of the same quality and therefore file size? How is it possible that some images on my camera can be 1.5 MB, and others 2.5 MB?
gpt
Basically, most images are in a compressed format. If a photo has a huge amount of pixels of the same color in a given area, the file format can record this as one piece of information. It's like when you're remembering a phone number: it's a lot easier to remember a sequence if you have two or three numbers that are the same in a row. So, a picture of a blue sky is going to be smaller than a picture of a Jackson Pollock painting.