Ilco explains checking the profile this way in their catalog. 

The squiggly lines associated with the part number is the profile of the key.  Profiles are PURPOSELY shown mirror opposite on our website and in Ilco's Directory.  If you are trying to check a profile of a key, start by doing the following:

• Find the key you are looking for in Ilco's Directory and PRINT it out to check profiles.  Many people avoid this step and try to do it by matching the images to the ones on their monitor.  It will NOT work. 
• Profiles can be found here.
  Most of the keys you will be looking for will be found in the yellow section.
  Domestic and Foreign Vehicles, including motorcycles, scooters, moped, ATV, RV, truck, tractor, equipment, boat and airplane will be found in the Automotive Keys Section.  Place your curser on PDF and choose your page alphabetically.
  Home and Office keys, along with most padlock keys can be found in Cylinder Keys.  Place your curser on PDF and choose your page alphabetically and/or by North American cylinder or International Cylinder.
• Lay your key over the image and check length, width, and height of you key blank with the one Ilco shows.  For the most part, EVERYTHING should match up exactly.  If the key you are looking at varies in height, measure from the shoulder to the tip of the key.  The shoulder is one or two tiny bumps on the shaft of the key nearer the head that stops the key when inserting in the lock.  They look like tiny noses.  Some keys have one shoulder, while some have two.
• Place the tip of your key onto the profile as if you are trying to insert your key into the paper.  Do NOT check the profile by pointing the key towards your eye.  This is a common mistake and many people order blanks that are mirror opposite of what they need.  Key blanks are NOT returnable, so follow the directions carefully to avoid ordering the wrong blank.
• Once you place the key onto the profile, look down ALL sides and check your keys pattern (profile) with what is shown.  If the profile shown matches your key EXACTLY, this is more than likely the key you need.  If it does not, find another blank that looks like yours and recheck the profile until you find one.  Some people cannot tell the difference between profiles because differences are very slight.  Order keys only if you are sure they are what you need as they are not returnable.