DevTools for Flutter and Dart gives the same result even after scaling images

I am playing around with flutter and building a simple quiz app. The project is almost ready to publish on play store and have several things to fix. but, I tried new flutter --analyze-size command and found out that I can reduce the file size more by scaling down images. I scaled images (it reduced the sizes significantly) and replaced the original files. then I ran a flutter clean and flutter pub get and ran flutter build apk --analyze-size --target-platform=android-arm64 just to test again. Although I reduced the image file sizes, the analyze tool shows the same sizes as before.

I also tried invalidate caches/restart option in android studio. but still the same result.When I selected two json files to compare in Diff option in DevTools, it says that they are identical files .Please, Can someone point me out how to fix this without creating a new project and moving files and assets?

btw I am on flutter channel beta, 2.5.0 on Windows 10

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