RECOGNIZING RALPH: It would appear that Ralph Lauren can’t even go to the theater unnoticed these days. At Wednesday night’s preview performance of “Hugh Jackman, Back on Broadway” at the Broadhurst Theater, the Australian multitalent opened the second act in a gold lamé outfit, which, he quipped, he had found at Lauren’s Rhinelander Mansion store. Taking the gag a bit further, he noted that the designer himself had been working the “till” at the time. Lauren’s presence in the audience, which Jackman then pointed out, may have had something to do with the extended riff. It must be all that Lincoln Center patronage.