I 100% disagree with the ruling, but this is apparently what the court had to say. They effectively sectioned out "expressive services" as able to discriminate, versus non-expressive services, like restaurants , which are still covered by the first amendment.
The decision suggests that artists, photographers, videographers and writers are among those who can refuse to offer what the court called expressive services if doing so would run contrary to their beliefs. But that’s different from other businesses not engaged in speech and therefore not covered by the First Amendment, such as restaurants and hotels.