By default, CSSPlugin uses a skewType of "compensated" which affects the skewX/skewY values in a slightly different (arguably more intuitive) way because visually the object isn't stretched. For example, if you set transform:skewX(85deg) in the browser via CSS, the object would become EXTREMELY long (stretched) whereas with skewType:"compensated", it would look more like it sheared in 3D space. This was a purposeful design decision because this behavior is more likely what animators desire. If you prefer the uncompensated behavior, you can set CSSPlugin.defaultSkewType = "simple" which affects the default for all skew tweens, or for an individual tween you can set the special property skewType:"simple".

Watch the video

Demo: skewType compensated vs simple

See the Pen
GSAP skewType comparison
by GreenSock (@GreenSock)
on CodePen.

Remember, if you hit the 360 button you could crash your browser as explained in the video.