The logo takes the theme from verse 261, Sura Al-Baqarah which explains how a good deed is rewarded (1x7x100=700) by Allah Almighty.
“The likeness of those who spend their wealth in the way of Allah is the likeness of a grain (of com). It grows seven ears and each ear has a hundred grains. Allah gives manifold increase to whomsoever He pleases and Allah is All-sufficient for His creatures’ need, All-knower.” (The Quran 2:261)
Spending for Hajj is a spending in the way of Allah.
Only Allah knows the real reward, here and hereafter.