Bizarre. Phones and tablets are definitely computers. We can attach a keyboard and a screen to it. We can print from it. We can attach mice. They can run arbitrary software, subject to platform restrictions.
That seems a fairly weak argument. Why can't they write a law that applies to all computers by default? including future form factors like wearables and glasses and anything not invented yet. This logic implies that the law has to be amended every time we find a new computer shape.
They obviously can, but according to the judge, they didn't. The judge basically wants them to go back and clarify what they mean when they wrote "computer".
Maybe the definition on the books says a computer is a device with a screen and a keyboard, and maybe other input/output devices like a printer or a mouse. Maybe it says something about typing on a computer, or sitting down at a computer, or such? It probably doesn't do anything like reference what the technical definition of a computer is (and funnily enough, if it did - even that would likely be wrong, and exclude things like analog computers, relay machines, mechanical differential analyzers, and a whole host of other things which historically and otherwise are "computers").
"A computer is a machine that can be instructed to carry out sequences of arithmetic or logical operations automatically via computer programming." https://en.wikipedia.org/wiki/Computer