These textures are just upscales with no extra work done to them. They are here so users can use the "GPU Texture Decoding" option without breaking mipmaps, with the added bonus of slightly higher quality. The texture "tex1_256x256_m_e4d4dfdd9664f87e_1_arb" is an interesting case. This dumps on the overworld for both World 1 and World 2, but the mipmaps differ between both. The final mipmap is the important difference: it is white in World 1 to illuminate the distance, and black in World 2 which means transparent in the distance. I chose to make the final mipmap gray to attempt to compensate for both situations. It's not perfect, but it's close enough. So it seems "tex1_256x256_m_a41696d6ef3997f7_1_arb" also has this issue. This one is used on both "Starship Mario" which has gray mipmaps, and "Yoshi Star Galaxy" which uses white mipmaps. The same problem exists, fixing it one area breaks it in another, and it may even be used in other places. I chose to go with the gray, as it's easier to look at than bright white when white is not expected. Unfortunately, there is no perfect compromise for this texture. I've included a JPG titled "notice.jpg" to illustrate this issue.