This is the first time Linda appears without Morbo (It happens again in "The Problem with Popplers"). According to the DVD commentary, the writers try to avoid putting Morbo into episodes that have a large focus on aliens. They also discuss the similarities of Morbo's voice to that of Lrrr's.
The broadcast of "Single Female Lawyer" takes 1000 years to reach Omicron Persei 8, but the Omicronians are able to travel to Earth in much less time. In the DVD commentary for this episode, executive producer David X. Cohen explains that the writers had decided that the speed of light would be increased in the future and that massive particles would still not be able to travel faster than light, but that electromagnetic waves from the past would still travel at their regular, lower speed.
In Lrrr's house, the door frames have three "horns" cut into them, presumably to make room for Omicronians to walk through without their horns hitting the frame. The same exists for the mousehole under Lrrr's TV, implying that Omicronian rodents sport three horns as well.
The space probe in the purple cloudish irregular galaxy seen when zooming away from earth at the beginning is the Voyager spacecraft.