It is a stressful place to work. Ability to multi-task/prioritise is essential. Standards are extremely high, and rightly so. In reality you are hard pushed to achieve that standard. It's the same in all of food retail, but it's monitored extremely closely in Lidl. Any oversight is picked up quickly, corrected and the person responsible is investigated formally or informally right-away. Accountability is very clear because there are very few people to chose from.
If you're a driven and highly skilled manager, then whatever happens you can justify your course of action. If you're just 'good', then forget it. The most important thing to note is: success requires a huge investment of your time, emotion and energy. There is no let up! You get home and go to bed because you are so exhausted, then you wake up and go to work again. Any (and I mean any) time of day is work time, 7 days of the week, even when you're on holiday.
If you care about doing a good job and you're prepared to work hard then understand it will take a lot out of you at Lidl. Manage your expectations about work/life balance. If you like to spend time with your friends/family, have hobbies, interests or want to go to the gym, you will not have the time or energy to invest in these things. They go on hold indefinitely.