Temporary fill the logo space with logoipsum until you have the real logo, because that top left corner doesn't looks good to be empty.

There's surely a moment when we need to explore layout or UI but we don't have name for it yet, let alone a logo for it. You stare that blank logo space with dead eyes and you start to fill it with plain square, but it doesn't look good. You start to make that square with a big X mark in it, but it just looks ugly.