The Sonos model S29 is the Symfonisk Picture Frame, which is as it sounds: a picture frame with a speaker built-in. Some details have been posted on the Verge, which confirm many of the details that I have been seeing since January.
The codename I saw on one prototype was “TITAN-redacted” which is similar to the Verge’s story.
The speaker specs are similar to the Play:1 and the existing IKEA devices. There is no mic and insufficient horsepower to run Alexa or Google.
I am guessing they would make great “invisible” rear speakers for surround systems, as well as being very spousal-approved audio devices in the home.
As the device is not on the FCC site yet it must be at least a few months from release.
The Verge article is here: https://www.theverge.com/2021/4/6/22370130/ikea-sonos-symfonisk-2021-lamp-wall-art-artwork-speaker