How are equity investments reflected in the accounting statements?

Trying to learn some basic accounting, and I had a question for the group:

I was wondering how SoftBank's investment writedown caused them to report a loss. From my understanding, the income statement only includes public/private investment losses once they're realized. It makes sense to me that the marketable and non-marketable securities on the balance sheet would take a writedown for their public and private equity investments. Why am I reading that net income was also affected by their investment losses though? 

Can someone explain how this would work through the accounting statements?