Michael Waltz got himself in trouble with the White House when, as national security adviser, he inadvertently added a journalist to a sensitive chat on Signal, a commercial messaging app.

Now, as he leaves that job, he has raised a new set of questions about White House use of the encrypted app. A photograph of him looking at his phone on Wednesday during a Cabinet meeting makes it clear that he is communicating with his colleagues — including the secretary of state and the director of national intelligence — using a platform originally designed by an Israeli company that collects and stores Signal messages.

This discovery of the new system came when a Reuters photographer, standing just over Waltz’s left shoulder, snapped a photo of him checking his phone.

He was not using a privacy screen, and when zoomed in, the photo shows a list of messages and calls from several senior officials, including Vice President JD Vance and Steve Witkoff, the special envoy who is negotiating on three fronts: the Israel-Hamas talks, the talks with Russian President Vladimir Putin about Ukraine and the Iran nuclear talks.

While the app that Waltz was seen using Wednesday looks similar to Signal, it is actually a different platform from a company that advertises it as a way to archive messages for record-keeping purposes. That is critical, because one concern that came up when senior officials were using the app was whether it complied with federal record-keeping rules.

One of Signal’s benefits is that it is both encrypted and can be set to automatically delete messages. But while that is a feature for users seeking secure communications, it is a problem for the National Archives, as it seeks to retain records.

It is not clear if Waltz began using the alternative app when he became national security adviser or after a nonprofit watchdog group, American Oversight, sued the government for failing to comply with records laws.

While the real version of Signal gets constant security updates and messages are kept encrypted until they reach a user’s phone, security experts question how secure the alternative app is.