I guess what Sindo is trying to say is that Playstation doesn't have itself tied to any particular character. And therefore isn't tied down to producing those games starring that character and thus can flex itself a bit on the sort of 1st party titles it makes. Whereas Nintendo will always have Mario, and yeah it works out very well for them. But means everything else is on a lower plane. And Microsoft have Masterchief and well..... He's dead and the studio who made him work for Activision.
Sony are quite into their 3rd n 2nd party work too, so I think for them having a mascot to push above all others would be detrimental to the relationships with other studios. (see Nintendo )
I'd say Naughty Dog are the Playstation Mascot makers. Crash for PS1, Jax n Daxter for PS2(...maybe) and Nate Drake on PS3.
Crash was very 90's, all bright colours n such. A platformer in 3D showing off the jump that 5th gen provided. I think it was kinda heavily marketed then as the Sony alternative to Mario n Sonic.
Jak not so much I guess. PS2 I wouldn't be so sure to say on a mascot.
PS3 NAte n the uncharted games line up very well. It's a semi realistic looking game, which is what they wanted to showcase with 7th gen. No silly bright colours n stylised looks, this was the power to make photorealistic places n people. It was a more fleshed out character, showing the mature audience they were aiming for. Movie like storyline for the blu-ray stuff.
So yeah I'd say SCE has no mascot like Nintendo n MS have. But the individual consoles kinda do. And at the moment Nate Drake and the Uncharted series are their flagship.