G-III Apparel (NASDAQ:GIII) saw its shares rise 10% in aftermarket trading yesterday. Sure, the company beat its internal estimates and boosted guidance for the year, but a little basic math has me questioning the strong reaction last night.

Sales increased 21% to $83.9 million, easily surpassing management's guidance of $75 million. The company did lose $0.05 a share, but that was much narrower than the $0.19-$0.24 loss that was expected. Management attributed the results to strong performances from sales of licensed brands by Calvin Klein, Guess? (NYSE:GES), Kenneth Cole (NYSE:KCP), and Sean John. This is typically a weaker quarter for the company, and management historically reverses its losses in the third quarter each year.

G-III designs, manufactures, and markets a broad range of outerwear and sportswear, and it deals in both licensed and proprietary brands. Its products are sold in upper-end department stores such as Macy's (NYSE:M), and Nordstrom (NYSE:JWN) as well as in more middle-of-the-road stores such as J.C. Penney (NYSE:JCP), and Kohl's (NYSE:KSS). Selling a diverse group of goods in a wide variety of stores that appeal to different demographics should provide some protection, especially in the current economic environment, in which lower-income consumers seem disproportionately affected.

The company raised its earnings and sales guidance for the year, and here's where the math becomes a little fuzzy for me. The company beat its quarterly guidance by $0.14-$0.19 a share. Yet it raised its yearly guidance by only $0.08, to $0.98-$1.03 a share. It's been a long time since I was in grade school, but doesn't this indicate that the company expects to underperform its expectations for the rest of the year?

G-III seemed to have a good quarter overall. That makes the yearly guidance and lack of third-quarter estimates all the more curious. For me, this stock won't get a fashionable look until I get a good explanation.