Welcome to the wiki & I deleted your image <3
Hey there, thanks for signing up & contributing to the Wiki. I thought I'd just let you know I deleted the image you just uploaded, File:Companion Cube.jpg, as we already have an image of the Portal Companion Cube and your image doesn't adhere to our image guidelines - specifically, it was low-quality and in JPG format.
I presume the image was taken within HLMV, check out this page on the TF2 Wiki. See section 1.2 "Dxsupport.cfg" to set up your HLMV to render in high-quality.