Edit: Two more months have gone by since I posted this question. Can there still be no news? Nothing for the two MarCo cubesats to take photos of; not even each other?
While InSight is still "under wraps" so to speak the MarCo's are free flying and fully operational and so should be able to use their attitude control, cameras, and direct links to Earth throughout the voyage to Mars.
The two MarCo cubesats are in heloicentric orbits, accompanying the InSight spacecrtaft to Mars. As InSight enters Mars' atmosphere and lands, the two cubesats will attempt to document the event and relay telemetry from InSight back to Earth using their pop-up flat-reflector antennas.
In early May 2018 Space.com's Bound for Mars, World's 1st Interplanetary Cubesats Phone Home said:
Radio signals from the cubesats, each of which is about the size of a briefcase, were received on Saturday afternoon, NASA officials said. [Launch Photos: See NASA's InSight Soar Toward Mars]
"Both MarCO-A and B say 'Polo!'" MarCO mission chief engineer Andy Klesh, of NASA's Jet Propulsion Laboratory in Pasadena, California, said in a statement. "It's a sign that the little sats are alive and well."
Since then I haven't heard much about the two MarCo spacecraft.
The August 20, 2018 NASA JPL news item NASA's InSight Passes Halfway to Mars, Instruments Check In notes that InSight is okay, and Space.com's August 20 NASA's InSight Mars Lander Snaps a Selfie at Halfway Mark to Red Planet even shows an internal "selfie" (below).
The Marco spacecraft are described in some detail in this answer, and it's cameras and one of it's images are discussed in Where is the camera on the MarCo cubesat that took this “pale blue dot” type of photo of the Earth and the Moon? and in the answers there as well.
Is there any further news about the two MarCo cubesats? I know that one of them had a leaky thruster and it's initial course correction maneuver was insufficient, but I don't know anything further.
Are there any publicly released further images from either one?
Are they at least transmitting data back to Earth?
below: "A 'selfie' taken by the InSight lander on its way to Mars shows components of the spacecraft." Credit: NASA/JPL-Caltech" From here.