What you are training
Low end is where mixes fall apart, because the bands are close together and small speakers hide them. Sub weight below 60 Hz, the fundamental around 80 to 120 Hz, the boxy region near 250 Hz, and the growl and string noise between 700 Hz and 2 kHz all belong to a bass guitar, and the difference between a full low end and a muddy one is usually which of those got the boost. This drill applies a move to a bass part and asks you to place it. Training on the real instrument matters here more than anywhere else: a 100 Hz boost on noise and a 100 Hz boost on a bass are different experiences, and only the second one is the decision you make in a mix. After eight rounds you will know whether your ear separates sub from fundamental, which is the first thing a kick and bass relationship needs.
After this drill, the plan: The daily plan pairs this with kick and bass balancing, so naming the band turns straight into the move that clears the low end.