I rang this morning to ask about taking photos and a nice man said no problem as long as I told a member of staff on each dept I was in.
By the time I finally got into town it was 3 o'clock and I'd only been in there 5 minutes when a tannoy announcement invited customers to wander about the building and take photos if they so wished. there were loads of people snapping away.
I'm now uploading some of the pics I took and will post them in small batches. I've started this thread before I post pix in case anyone else was there taking any and was looking for somewhere to post them.