I am not VC but I think this is kinda apparent from the get go.
In early stage you are betting on and nurturing a small team with a full-of-hope business plan. They need relatively small bits of help that can go a along way. So both "who you are chosing among" and "how you are helping them" is very specific.
With bigger companies, the team and the business plan is more proven and they need help navigating size and scaling their offering - a very different set of people you are chosing from and what they need from you.
In early stage you are betting on and nurturing a small team with a full-of-hope business plan. They need relatively small bits of help that can go a along way. So both "who you are chosing among" and "how you are helping them" is very specific.
With bigger companies, the team and the business plan is more proven and they need help navigating size and scaling their offering - a very different set of people you are chosing from and what they need from you.
I am sure there's a lot of additional nuance.