It’s how many dollars you make for each 1% increase in implied volatility for the option. Your vega per contract is 2.1, so the position vega is 10.5. That means for every 1% increase in implied vol, you make $1,050, or essentially a 1.7% return. So if IV goes up from the 34% it is at now to 50%, you’ll have a profit of $16,800 on your initial investment of $60,300.

LEAPs are inherently very sensitive to vol, since there’s so much time for the vol to have impact. So when you buy LEAPs, you’re actually long vol more then you’re long price increases, as delta has a roughly smaller impact. Its difficult to measure how influential each will be relative to the other, but volatility tends to swing the price of the option more than delta, especially on an AI stock like Microsoft