Pictures or video are not the point of the mission. And it was nowhere certain that we'd even get that initial picture right away, as it depended at least one of the two experimental MarCO nanosats doing its job as a relay. They successfully did just that which was great; otherwise we'd have had to wait for several hours for one of the orbiting assets to relay the data. Radio doesn't work if there's thousands of kilometers of rock in the way, as you might know.