Well, this is weird.

That’s a photo of a security scanner just outside the Westfield shopping centre in Stratford, east London, sent our way by a helpful CityMetric reader on Monday.

Westfield Stratford City, for those who haven’t had the pleasure, is not a major international airport: it’s, well, a shopping mall. Full of, y’know, shops. It’s not the sort of place you generally require a fully body search to enter. And yet:

Who they are scanning, we have remarkably little idea. That one single security gate looks pretty easy to get around, so presumably Westfield staff are picking and choosing their scan-ees very carefully, but that’s about all we can glean from the pictures themselves. What they’re scanning for, or their reasons for thinking this necessary, remain clouded.

One possibility is that this relates to the unveiling of the new 9/11 memorial, in the Queen Elizabeth Olympic Park behind Westfield. That happened on Tuesday and was, by most accounts, a pretty high security sort of affair. But the new memorial is, by our count, a good third of a mile from that checkpoint and you don’t have to pass it to get there.

We asked the press team at Westfield Stratford what was going on, several times, but no one was available to speak to us: should that change we’ll be delighted to update you on their insights.

Until then, answers on a postcard.

UPDATE: Westfield have belatedly been in contact:

Westfield’s policy is to not publicly discuss security procedures, however the safety of our shoppers and staff is a key priority. Westfield implements various security measures and practices including random searches at the entrance to centres, as precautionary measures.

So – still no idea, frankly, but this time at least our cluelessness is official.