When Batman uses his rappelling line to follow Robin, the shot changes to him doing a somersault on a rooftop, but the background plate remains the same.
Zarbor was very meticulous when he created his base of operations. The computer even says "Made On Ergo", which then gives Bat Mite the answer as to where the Dynamic Duo and the villains were transported to.
In part 1, Zarbor was seen creating his base of operations with his powers, right down to the computers and other equipment. For some reason, after he leaves Earth for Ergo, he leaves everything behind instead of either destroying it, or at least making it disappear.