Bug: Copying image files from Finder pastes a thumbnail instead of the actual image

[hakonharnes]

Description

When copying an image file from Finder and using pngpaste, the resulting image is not the actual image content but appears to be a generic thumbnail or icon. This differs from the behavior in other applications (e.g. Google Docs), which correctly paste the full image when the same file is copied from Finder.

Steps to reproduce

1. Open Finder and copy an image file
2. Run pngpaste output.png
3. Open the output image

Expected behavior

The pasted image should match the contents of the file copied from Finder.