Dynamic Component :: The Dynamic Component icon identifies Podium Browser items with DC options available to users. Dynamic Components allow users to customize Browser components in various ways. For example:
LEM - Light Emitting Material :: The LEM icon is used for light fixtures that employ Podium LEM materials as an illustration source. Unlike Omni and Spotlights, Podium LEM materials use actual SketchUp geometry to cast illumination into a SketchUp scene. LEM materials can be made invisible for use as "fill lights," or can be used as a visible illumination source (like a lightbulb, neon sign, etc.)
Spot Light :: This icon identifies light fixtures that use Podium Spot Lights. The Podium Spot Light is a directional light source that emits a cone-shaped light field with user-defined settings for the cone angle/width, and falloff (edge hardness/softness).V2 Plus :: This icon indicates that the Browser component uses new V2 Plus material properties. These items are still usable in older versions of SU Podium, but will not render with V2 Plus properties. For example, an item that uses the Podium V2 Plus metallic material type will automatically render using the closest approximation available in older versions of Podium.
If you have not updated to SU Podium V2 Plus, you can read about the differences here.