Dunno. Clothing is usually displayed by combining the naked girl with the clothing item(s) and the blinking eyes ingame. And items that are not a full suit are displayed in the wardrobe with their own icon. So there are many options to show that stuff in the wiki, with and without the girl.
As for format, this is comic colors, maybe saving screenshots as png is better than jpg, but difference will be marginal. The resolution of the girls tiles is 390x700, so any caps should not have a higher resolution than that.