My understanding is in the US, in modern times, the freedom of expression is only restricted in cases where some other law would otherwise come into play. For example I could express myself by suggesting I would pay someone to commit a murder for me but I would still be charged with criminal conspiracy to commit murder. Since the US is not an Islamic theocracy we have no laws on the books regarding the physical depiction issue. Basically I think you could say the freedom of expression is paramount in all but a few very specific areas and we have a special flare for protecting freedom of expression in relationship to religion since this country was founded also on religious freedom. I'm probably not representing the actual argument properly but I think it's pretty close.