I can't believe you people are getting hung up on this. Apparently they let her IN wearing the Tshirt, it's not like she would have changed in the gallery.
"Apparently they let her IN wearing the Tshirt, it's not like she would have changed in the gallery."
she was wearing a jacket over it, when she got seated she was oh so hot from climbing the stairs that she decided to take her jacket off. that is when her t shirt was spotted.