To summarize, the building blocks of life have handedness, and scientists are looking into studying what would happen if you flipped that handedness to the opposite side. If this mirror life were to escape containment, the affect it would have on the planet's ecosystems could be catastrophic. Outside of satisfying curiosity, studying mirror life has few upsides, and may not be worth the risk.
So, of course, we're going to do it anyway.
Edit: Apparently, Anton already did a video on the topic months ago, and I missed it.