Has anyone noticed this weird behaviour in Apple’s Photos app when browsing images shot in RAW format? Let’s say you shoot a photo in RAW and then switch to Apple’s Photos app. Tapping on the thumbnail brings up the image, and after a few seconds, the image gets changed to a lower-quality version. Contrast is lost, and exposure is somewhat lowered. The result is a dull image. My possible explanation is that the thumbnail is a JPEG post-processed interpretation of the RAW image that is presented in the UI. When tapping on the thumbnail, the RAW version gets uncompressed and presented, which replaces the full-size JPEG preview version, hence the image quality degradation. 

Do you have a similar understanding, or do you have another explanation?