What's happening to my little Gorilla Cookies?

Some parts of your plant and the trichomes on them are older than other parts of the plant. Where you are seeing mature trichomes is on the sugar leaves, some of the 1st places to get trichomes. There seems to be a misunderstanding with trichomes and people think they all magically mature at the same time. This is not how it works, just like an orange tree, some will be ripe before others because they started to grow before others. If you could only harvest the whole tree (like with weed), then you wait till most of the oranges are ripe. By that time some will have fallen off and others might still be green. This is why I always suggest to look at the whole plant to get an idea of overall ripeness of the plant.