The idea that you should lift with your legs instead of your back is, to put it bluntly, fucking retarded. It is some made up corporate slop from the 90s where they didn't want office workers to call in workers comp when their backs seized up trying to pick up a paperclip off the floor.

Deadlifting reasonable loads with good form and adequate recovery is one of the best things you can do for long term back health, because it makes your back stronger. If you work up to a 2x bodyweight deadlift (which is considered the standard in a broad number of sports to be considered reasonably athletic), and then just go into the gym once or twice a week and maintain that standard for the rest of your life, then the odds that you will tweak your back picking up a paperclip are quite small.

In lifting circles, the round back deadlift or deadlifting when there is spinal flexion or extension tends to get a lot of hate. But again, Specific Adaptation to Imposed Demands rules - if you are lifting reasonable loads and allowing for adequate recovery between sets and training sessions, our expectation is that these "bad" lifts will actually make you stronger and more resiliant to injury in the future. If you want to be a world class strongman competitor, then you may very well tear up your back maxing out on the atlas stones. But if you train within your limits without ego, then you can include atlas stone lifts in your training for many years and reap the rewards of having a back that is strong and healthy not just in the straight-backed traditional deadlift position, but also in the more awkward curved position that the atlas stone demands.

And all this is clearly very reasonable, since your body evolved to handle real life, which does not confine itself to the laboratory-like conditions of deadlifting a barbell - let alone the corporate cartoon description of lifting paperclips put up in your office breakroom. For literally millions of years, humans have been lifting heavy rocks overhead to build shelters, scooping up writhing toddlers off the ground, and wrestling aligators onto land for a meal. The hip hinge is the most powerful movement in the human repertoire, and the idea that it is bad for you to do it is ridiculous.

Sure, we can sit here on the internet and critique her form in this way or that. But at the end of the day, she is lifting an awkward load a single time as a sort of circus trick, so it doesn't matter. Good Lift!