The Tensile modulus (Microcellular) result indicates how much stress is needed to cause a unit of movement
You do not need a fiber-filled material to produce this microcellular result, because the bubbles themselves will affect the mechanical properties of the material.
Tensile modulus is a mechanical property value. The distribution of this mechanical property is used by the structural analysis for its performance evaluation in a Stress analysis.
Compare the results in each of the different principal directions. You should expect more force to be required in the direction of flow (first principal direction) than perpendicular to the flow direction (second principal direction). If the molecules are aligned in the first and second principal directions, then the tensile modulus will be different in each principal direction. If the molecules are randomly aligned, you would expect to see a uniform tensile modulus result in each principal direction.