There are 2 racks of WSOP chips used by the Rio in WSOP bracelet events. One rack has a much larger quantity that the other, so Rack 1 gets used during the small buy-in events, usually $1,000-$3,000, plus the $10,000 Main Event. Since these events draw larger fields, the quantities available in Rack 1 get used. Rack 2 has a smaller quantity of chips, so they only get used during the high buy-in events, usually $5,000 and up.

Rack 1 chips are of this style:

Rack 2 chips are of this style:

...by the way, the $5 tournament chips above is only used as a re-buy chip, making it fairly rare.

Rack 1 has a white background on the inlay and Rack is not. Also, the inserts are of a different style. During the WSOP the Rio also holds non-bracelet WSOP events, such as sit-n-goes and nightly satellites. These tournaments use more common tournament chips, many of which are simple clay hot-stamped chips or non-clay plastic WSOP logo chips. Some of these you've displayed in your first scan. Hope this answers all of the questions. Good luck.