No, the directions in the chart that you posted don't say 2 different things. It says in the yellow box that only the RS rows are on the chart and to purl the WS rows. The chart key is a universal one used in charting software and gives instructions for both RS and WS boxes even though there aren't any WS boxes on this pattern. Other patterns may use the WS row directions, but the key can't be edited for those that don't. Look at the numbers on the R edge of the chart, they're only the odd ones, the RS row, there are no even rows on this chart. That's another clue that you won't do the chart on the WS rows, so just ignore what it says for them in the symbol key. IF the WS rows were included on the chart you'd do the WS row instructions for those boxes.
More clear now?