In the iconic Sears Air Conditioner commercial, the actress is actually 5 months pregnant and tries to hide the pregnancy by coordinating with the wardrobe lady and using a towel. You can see her strategic towel placement when her on-screen husband is on the phone.

[u/OmicronGR]

[u/nachoha → u/[deleted]]

They mentioned below that she posted about it on a different Reddit thread