The splashback in the kitchen is a bronze tint mirror. I haven’t come across any issues with mirror looking warped – this would usually only occur if it was a material that had some flex to it.
This is what was specified below however, the builder may have used an alternative supplier.
Please note that not all mirror products can be used behind cooktops. You will need to check with the supplier if the product you are looking to use is heat resistant.
EWERT LEAF PTY LTD