Dropped Items can be picked up through blocks

Bouncing items can be picked up by player through blocks

You can trigger it by
1. Place 9 slime blocks on top of 1 sticky piston
2. surround the slime block with four droppers
3. cover the top with glass (3x3, no border)
4. Create a redstone clock connected to the piston and the droppers
5. Activate the clock and stand on the edge of the glass
6. You should be able to pick up the stuff inside the glass

That's it!