The Pick Up achievement is NOT from picking up literal items in the level but from walking over the little blue orbs that can be found throughout a level. There are 3 in each level and for some you will have to be a specific height to reach them. This guide is less about HOW to get the orbs are more about where the orbs are located as there are many ways one could easily REACH the orbs.
1) Across from the computer monitors is a mini fridge. Open it to find the orb inside. You need to be decently small to reach this as you will have to go inside the fridge for it.
2) On top of the cabinet directly above the code combiner.
3) There are two desks back to back in the center of the room. Go under the desks and look towards the side the fridges are not on. The orb is between the desks.