Fact Check: Why does an oximeter display ‘oxygen level’ of pens?

In the midst of the deadly second wave of Covid-19, a video of an oximeter displaying the "oxygen level" of a sketch pen is making the rounds on social media.

Amid the deadly second wave of Covid-19, pulse oximeters have become a household gadget in India. However, a viral video showing an oximeter displaying the “oxygen level” of a sketch pen has left many puzzled and shocked. People sharing the video are calling oximeters a scam that are fooling people and creating unnecessary panic. The video shows a child inserting a sketch pen inside an oximeter and turning it on. The oximeter shows a reading. An adult standing close to him comments, “Oh, a sketch pen also has a heartbeat! Vande Mataram friends! See this, a sketch pen’s heartbeat and its oxygen level! Media is unnecessarily scaring people. Sketch pen has a heartbeat of 200 and oxygen level of 98. What sort of hypocrisy is this? Beware of this. Why is this unnecessary panic of falling oxygen levels?”