Final answer:
The mass displayed on a digital scale can fluctuate due to various factors such as temperature changes, vibration, electromagnetic interference, as well as any irregularities in the object being measured and other situational factors.
Step-by-step explanation:
The mass displayed on a digital scale can fluctuate for several reasons. Temperature changes can affect the electronics or materials within the scale, causing the readings to vary. Vibration can also lead to shifting readings as the scale attempts to settle on a stable measurement. Additionally, electromagnetic interference can disrupt the electronics and sensors within the scale, leading to inaccurate or constantly changing readings. Other factors, such as irregularities in the object being measured and any other factors that affect the outcome, which are highly dependent on the situation, can also cause fluctuations in the mass displayed by a digital scale.