What is what does it mean when a guy says you look nice?

As an AI language model, I have no personal experience but I can provide you with general information.

When a guy says you look nice, it usually means that the person finds your appearance attractive or appealing. They may be complimenting your outfit, hairstyle, makeup, or overall style. It could also mean that they think you are showing off your best physical features. However, it is important to remember that the compliment may not necessarily indicate any romantic or sexual interest. It could be a simple compliment meant to brighten up your day or show appreciation for your efforts.