Continuity mistake: When Walt is talking to Saul near the start, we see him unbalance the scales on the table in front of him then lean back. Camera cuts to Saul for a few seconds then shows Walt from behind Saul. In this angle, the scales are now balanced. (00:16:50)
Continuity mistake: Mike Ehrmantraut takes Jesse to a house in the desert. He pulls up behind a dark blue car, which vanishes in the next shot, and then reappears.
Continuity mistake: When Jessie, Victor and Mike pull into Gus' chicken plant they pull up behind Gus' car, but when they get out the car is gone, and when they start to walk to the building the car is back.
Chosen answer: It is part of the ritual for la Santa Muerte. It is a sign of humility and sacrifice.
djm