The photo import window reads photos by folder. If my 32GB memory card has 14 folders, it doesn't show anything until it finishes reading all the photos in one folder, then appears to hang for a while until it finishes reading all the photos in the next folder, and so on.
Three possible methods exist:
1- to display each photo as it's read without waiting for all the photos in a given folder to be read,
2- as is,
3- to not display thumbs until all of them have been read.
Ideally I would like method 1 as it gives me the quickest feedback. With method 2, if you have 1000 photos per folder, that's a lot of waiting. Method 3 would be worst for the same reason that method 2 is not good, it would just be far more severe.

Reproducible: Always