Screen brightness on Android/Samsung devices

[gray2018]

So, I have been noticing this for awhile. Recently, I have owned the Note 9, Note 10 Plus and Note 20 Ultra. Obviously, each device's screen should be brighter than the last. But I swear, it seems like at certain times, some devices that shouldn't be can be brighter than the other. Sometimes it seems like my N10+ screen is brighter than the N20U, sometimes the Note 9 seems brighter than the N10+. When setting up your screen with certain wallpapers or icons, can this effect the overall brightness of the screen sometimes? It seems like not too long ago, on one of my devices, I changed the icons, and it almost appeared brighter afterwards. Now this also makes me a wonder, is this a Samsung thing or overall Android thing? Or am I just crazy here?

In terms of settings, I keep my devices all the same using dark mode, full brightness. And I make sure to not apply dark mode to my wallpaper. I would love to show a picture of an example, but it's kind of hard to get an accurate one.