In Vedic astrology, the three outer planets of Mars, Jupiter, and Saturn each cast a special aspect.
Their movements and energies are not just relevant as "archetypes" - they represent real forces, eternal forces of the universe that transcend our 80 to 100-year lifespan. They connect us to that eternal, cosmic nature that we forget here on the flat Earth in which we live in our day to day lives.
Each of these planets is a body of light that can "see" in different directions. Saturn sees 3 signs in front and 10 signs in front. That is his special look. This look conveys the essence of his nature.
With Saturn occupying Leo, he will be "watching" the sign of Libra and the Sun of Taurus for the next two years, both ruled by Venus. If anyone has planets in Sidereal Libra or Taurus, Saturn will also be watching them.
Regardless, wherever those houses fall in your Sidereal / Vedic chart will be under his watchful eye. Saturn's aspects create trouble by shattering our illusions around the things he sees.
Sometimes this results in losing the thing entirely, other times we may just worry about it or have to put forth immense effort in order to maintain it.
This process of worry/effort/potential loss forces us to either deepen our commitment to it or let it go. This is why we tend to lose things when Saturn starts moving. He tends to push things to a point of seriousness where they either break or we have to work to improve them.
There's a great story about Saturn aspects, Saturn's "looks".
So the great goddess upon seeing Lord Saturn unmoved by the festivities asked him why he was not participating. Saturn replied, "Great Goddess, your child is beautiful and I do not want my looks to ruin that beauty - a glance from me is not always welcome". "Nonsense!", declared Parvati, "I insist you look at my child immediately!". At this time Lord Saturn gazes gently at the beautiful Ganesh. No sooner did Saturn look at Ganesh, than the beautiful boy's head fall off!!
And so it is said that the Saturn aspects can be more difficult than the Saturn conjunction.