The original question asked about "closely packed, but uncompressed" blueberries. I think it's more reasonable to assume this means berries with a small amount

The original question asked about "closely packed, but uncompressed" blueberries. I think it's more reasonable to assume this means berries with a small amount of air between them (the state of blueberries as the writer was probably thinking of them), rather than a void-free blueberry mass, or blueberries with pockets of vacuum between them.