attract, captivate
惹 centers on drawing someone in emotionally or mentally: attracting interest or captivating attention. Both given meanings are natural expressions of this pull.
惹 combines 若 (young, possibly contributing sound) with 心 (heart/mind), suggesting something that pulls at the heart or mind. The exact historical development is uncertain, but the phono-semantic structure is plausible.
The top 若 looks like a young plant drawing attention, and the bottom 心 is the heart. Picture a young, captivating idea growing and pulling at your heart: 惹 means attract or captivate.
For ジャク, imagine a jack-in-the-box suddenly popping up and captivating everyone: jack -> ジャク, and the surprise attracts all eyes.
to draw (attention, sympathy, etc.); to attract (e.g. interest)
bringing about; cause; provocation
to feel attracted by; to be fascinated by
to be charmed by; to be attracted to; to be taken with; to be drawn to
to charm; to attract; to fascinate; to entice
catchphrase (esp. in advertising)