Those who have a passport other than that of Thailand can get a tourist card and receive the following discounts and benefits

・Up to 30% discount at about 100 affiliated stores
・5% discount on regular priced items at Siam Takashimaya
・Up to 6% VAT refund
・Free use of the tourist lounge on the 1st floor
・Free WiFi

You can apply for such a tourist card at the tourist counter on the 1st floor, but I recommend registering online in advance

Online registration page for tourist cards that can be used at ICONSIAM https://touristreg.onesiam.com/?username=I...

List of stores where you can receive discounts with the tourist card
https://campaign.iconsiam.com/downloads/to...