Fan boys-ahh pooh!
It's 19-21 pixels high by 350 to 500 pixels long (horizontal max is critical). In Photoshop pinch the camera from one of Mo's original tags. Use one of several selection methods to reduce this to 'just the camera'. Create a new document with a gradient layer, text layer and the camera on a layer. Flatten it and upload via the user cp. It's trial and error and retry.
Now to that fan boy nonsense: I've got two Nikons, a Canon, a Yashica twin lens, a Seagull, a Polaroid, several pinholes, and the Pentax(s). And I truely lust for a Leica. As soon as Mo extends the horizontal width restriction, you want I should list all this gear?