Of course "stem" is a misnomer as this is a coral which is an animal. When these stems take in water a clump of dense color becomes a soft coral "bush". This image is just the last few inches of a branch of coral. To see clumps before the stem takes on water see the red, orange and pink parts of Crinoid and Soft Coral Bouquet. For a full bushy view go to Light Pink Soft Coral with Crinoids or Red on White Soft Coral. See also Orange Soft Coral Stem.
This square version of the image has a maximum size of 8 x 8. See also the oblong version Light Pink Soft Coral Stem.