First, make sure you understand the difference between content icons that load geometry into the scene and content icons that modify geometry that is in the scene. Icons in FIGURES, HAIR, and PROPS load a model (geometry) into the scene. This could be a human figure, a clothing figure (V4 Morphing Fantasy Dress), a weapon (prop), or dozens of other items. Each of these is a model. Geometry or the shape of the model plus any applicable rigging is loaded into the scene when you double-click one of these items. Sometimes a default texture is loaded also with the geometry, but this is not always so.
Icons in POSES modify the geometry (model) loaded into a scene. They can add and apply morphs, apply a texture, or actually change the pose of the figure. By themselves, they do nothing. You must have the appropriate model loaded and selected. Then you can apply a POSE to the model (FIGURE, HAIR, or PROP). Many POSES are in fact MAT POSES. A MAT POSE (Material Pose) applies a texture to a figure. Many products are simply texture add-ons for another product.
For a POSE to work properly, the applicable model must be loaded and selected. In DAZ Studio, a model (FIGURE, HAIR, PROP) is selected when its top name is highlighted in the Scene Tab. For example, a texture add-on for the Morphing Fantasy Dress is provided as a MAT Pose. The Morphing Fantasy Dress must be loaded into the scene and selected. Then when you apply a texture preset for the MFD (Morphing Fantasy Dress) by double-clicking it, the texture of the MFD changes to that texture preset. If you try to apply a texture add-on for a hair product to the MFD, nothing will happen to the MFD, since it is not the product for which that preset (Hair texture) was intended.
Mat POSES (Texture presets) can change the texture of anything–human figures, human clothes, accessories, buildings, and so forth. They make content very versatile.