Building a gate the right way - GIF

[Floradawg]

Of course. I was taught to always put members in tension, because if they are in compression they can deform perpendicular to the force applied and bend out of shape.
Compression works fine as long as the member itself has enough rigidity to withstand any side loads that are imposed. Wood would definitely warp and cause issues under compression unless massively oversized. This adds weight and expense.
Think about if you were using twisted wire as the diagonal brace, you would want it in tension as it is useless in compression.
Because the tension member was not properly anchored in this video, it is miss-leading.

You are correct. A turnbuckle and rod would only work one way but a properly attached wood member would work in the same orientation as the rod or opposite.
Who is this miss-leading. Is she pretty?