Is pure shear any different from flattening? If not, what makes them different?

Question

I have had a difficult time visualizing what exactly sets pure shear apart from flattening in an object. On a surface level, it seems that for both when a force in 1 direction applied to an object is greater than the forces applied in other perpendicular directions, the direction where force is the greatest experiences compression while the other directions perpendicular to that greatest force direction experience elongation. Is there anything that separates the two when the end result seems to be visually similar? If so, what is that difference?

In: Physics

Answer 1

Whoops, fudged the title a bit. should be “If so, what makes them different?”