The crab apple’s fruits dress the tree for the coming season.
Here they are just waiting for some robin–or next spring, perhaps a cedar waxwing–to imbibe.
In my lectures, when I mention crab apples, so many folks turn up their noses, remembering the messy trees of their youth that dropped larger “apples” all over the lawn.
These newer trees are bred to have “persistent” fruit” meaning the fruits stay on the tree until the birds come to eat it. It can make a very lovely show–almost as nice as any deciduous holly.