Mobile robots are equipped with various sensors to perform object detection, localization, and navigation. Among these sensors, LiDAR (light detection and ranging) is the most widely used sensor for environment map creation. However, LiDAR-based localization is challenging in modern environments containing specular surfaces, such as mirrors and glasses, that cause light reflection, penetration, or diffusion. These conditions make the obtained map inaccurate, unreliable, and noisy. This paper presents the effects of mirror-like objects in various indoor arrangements on 2D LiDAR-based maps. Experiments were conducted using a mobile robot equipped with LiDAR navigating in an environment with several mirrors. Experiments suggest that laser scans may be fully reflected off mirrors, causing no range or intensity data and creating a faulty map. Objects or boundaries within the range of LiDAR may be mapped behind the surface of the mirror, and robot self-detection may occur on the surface of the mirror. This situation exacerbates when more than one mirror is present in the environment. The results presented in this paper can aid the development of LiDAR-based indoor navigation to identify and remove inconsistencies created in LiDAR maps due to mirror-like objects.