This is the scene of the ledge on which the box spring rests. This wooden ledge is factory covered with a fabric like material which is pitch black.
Without decent light and more than a glance look this would remain hidden.
The white eggs look almost like glowing in the light. You can see the light reflected in the black extruded feces as well.
Point is even though this picture has great clarity, in normal circumstances, this is very easy to be misses by a casual observer.
This situation depicted in this image is that of a well established infestation but not to the level where it would be in your face. If the residents were not experiencing bites or skin irritation, they may not become aware of bed bug presence. In typical light the significance of this situation can be overlooked.