[TokuKnight89]

So, why do some Sentai like to make a certain arm gesture when announcing their attacks (usually while in cockpits)?

Granted, it's more a compliment to a dramatic announcement given that stunt actors can't visually emote using facial expressions while their faces are covered, but it still comes across as... questionable.

This is most obvious in Zyuranger and Dairanger, and by default, the early days of Mighty Morphin'.

https://sirstack.db-destiny.net/morphylogeny/127.htm

It could be because the gesture doesn't have the same amount of cultural/sociopolitical significance in Japanese society, but even that feels off cause the Shocker grunts of Kamen Rider would do a variation of the same gesture given Shocker's origins/affiliations.