Snails when focusing and feeling non threatend like to move their eyes closer to what they are working  on to get a better view. Snails sight is not good, its only monocromatic (black and white) and they can not focus their eyes. So they need to get physically closer to check out what they want to see.

Snails sometimes will look a bit droopy almost like they are deflated. This is usally a good sign. As long as it does not appear to be bubbing or has retracted so far back into its shell that you can not see it (Which will happen when your snail is very sick or has touched somthing physically harmful) This droppyness without any other signs just means that the snail is sleepy and feels safe enough not to retract before it starts falling asleep. As snails feel safe they will sometimes sleep partially out of its shell.

A behavior that you may see often is a fully strecthed out snail. They do this when going about their "Snail chores" or daily tasks. This can be when exploring or going towards somthing that it wants such as a wall to climb or food that it want. In addition it does it when trying to figure out somthing which is non harmful such as when sitting on a new surface, when taking a bath or being handeled