The Louvre is just gigantic. You could spend a week there and still not see everything. But they really make an unhealthy fuss over the Mona Lisa.

The main (but not only) entrance is a huge queue from level -1 up to floor 2 to see the portrait! Though it does move pretty fast. All the signs along the way only point to the painting. You get the impression there's nothing else in the Louvre at all.

They let you get pretty close, but only in small groups. Time is very limited and museum staff basically rush people out when their group's time is up. It's funny, but almost no one even tries to actually look at the work. Everyone just takes 100500 selfies for memory and leaves.

The first thing you see after leaving the Mona Lisa room is a sign pointing to the exit :)

PS. This might be because they temporarily moved the Mona Lisa to a different room upstairs due to renovations.