From the complaint in Allen v. English:
Plaintiff Yvonne Allen is a devout Christian woman who covers her hair with a headscarf as part of her religious practice. In December 2015, Ms. Allen sought to renew her driver license at the Lee County driver license office, where officials demanded that she remove her head covering to be photographed. When Ms. Allen explained her religious beliefs, the County officials responded with a remarkable claim: They admitted that there was a religious accommodation available for head coverings, but contended that it applied only to Muslims.
The ACLU press release adds:
Lee County’s refusal to grant Allen a religious accommodation contradicts state rules and violates her rights under the First Amendment to the U.S. Constitution and the Alabama Constitution, according to the lawsuit.
“The county’s interpretation of state rules blatantly violates the First Amendment,” said Susan Watson, executive director of the ACLU of Alabama. “The government cannot discriminate between faiths in granting religious accommodations.”
Heather L. Weaver, senior staff attorney for the ACLU’s Program on Freedom of Religion and Belief, agreed. “The county’s policy is puzzling. There is absolutely no reason to restrict accommodations for religious headgear to certain religions. The Constitution protects both Christians and Muslims and, indeed, people of all faiths.”
Sounds right to me. The First Amendment doesn’t generally require government to give religious exemptions from generally applicable laws (such as requirements that people have driver’s licenses that show them bareheaded) — but when the government does grant religious exemptions, it generally can’t grant the exemption to members of one religion and then deny the same exemption to members of other religions. The Alabama Constitution also presumptively requires religious exemptions (Alabama has a state constitutional amendment that tracks the language of many Religious Freedom Restoration Acts), and while exemptions can be denied when necessary to serve a compelling government interest, it’s hard for the state to credibly make the argument that Christians must be denied this exemption when the state thinks that granting the exemption to Muslims poses no problem.