Always one of the most affordable and popular items in the catalog, it was easy to throw one in with any order. The style (as evidenced by eBay listings) is classic “Henley” but they called it “The Banana Republic shirt” at the time. It was simply their Yukon Shirt in off-white with a logo on the left breast.
The Banana Republic shirt dates back pretty far, it was always in the catalog (check the catalog thumbnails at the bottom of this post). Note the tags in the photo examples above. One is obviously a late model with the Travel and Safari logo, while the other retains the manufacturers “Healthknit” shirt. I think this example may be from the earliest catalogs before the Stars and Bananas tag, but there’s no way to know for sure.