But who knows? Maybe the analogy is correct. I don't think we can say. In fact I would even wager that a "center" is more likely... because can you even imagine a real world analogy where something expanding has no center?
If you can't then there probably is some sort of center.
Example: the number line. You might be tempted to say 0 is at the center but… there are an infinite number of things on either side of any number you choose.
Additionally nobody knows if the universe is infinite.
I also stated that no real world analog of a perfect expanding sphere exists. Because we can't imagine an analog it's much more likely that the universe DOES have a center similar to the nozzle.
Try to imagine a real world analog to the expanding geometric sphere without a point of discontinuity. You can't. And because you can't maybe it doesn't exist. Maybe it does. But not being able to imagine a real world analog is slight evidence that there there is a center.