Short Reach is the horizontal measurement from the horizontal top of the bars to the front curve. It accomplishes a couple of things: decreases the total length of the cockpit (seat to hoods) and decreases the volume of the drop so someone with small hands isn't hitting her forearms on the top bar when riding in the drops (a bit of flare of the drops can help here also).
Short Drop is the vertical measurment from the horizontal top to the bottom of the drop.
The reach to the levers has more to do with the bend of the drop. As you research bars, be very careful that you understand that reach can mean different things.
The very elegantly translated Deda Elementi site talks about the bend's affect on reach to the lever:
The use of anatomic bendings has been spreading for many years and has supplanted the bendings conceived by past champs. Neverthless the last ones had and have the advantage of an easier gripping of the brake lever, if necessary. The gripping of all anatomic bendings is more difficult in case of users with small hands and not so easy for the other ones.
Deda Elementi has conceived an ANATOMIC version of any of its bendings with easier gripping thanks to a distance which is 13 mm. shorter than the one of all other bendings on the market.

