What's with those funky Olympic Weapons?

[FfNJGTFO]

I've been watching the Rio Olympics shooting events and, except for the Shotgun events (which seem to use regular *and rather expensive* OU's), the weapons seem to have the strangest designs... nothing I've ever seen in competitions such as IDPA, USPSA, etc. I guess these are ISSF standard weapons??? See some example pics, below:

Pistol Rifle




What's with those designs??? Why not use "conventional" every day weapons?