The display setting in Studio's element (or feed) properties page allows you to exclude content in your feed from being sent to the creative upon impression, which is useful for decreasing the data payload of the ad. Any dynamic element that is used by the creative assets must have the display setting switched to ON .
By default, the display setting is set to ON for all columns. If you toggle the switch to OFF for a certain column in your feed, the content in that column will not be sent to the creative (or the payload).
If you select a targeting data type for a certain column (e.g. placement ID, geographic type, etc.), the display setting toggles to OFF automatically, but you can switch it back if needed.