This is classic PlayStation 2 game Ico running on Yoshida's Vita. It might not be his Vita—it could be someone else's. But, yes, it sure is Ico!
This is a not-so-subtle hint that Ico, which was re-released in HD on the PS3, is getting PS Vita enabled remote play. Here, Yoshida is testing it out.
"We are almost ready with a patch," added Yoshida. "Beautiful on OLED. More info soon."