No one will think to look under there

found on Imgur

On the plus side, it is very close to the same colour as the mat, so you might argue that it legitimately is blending in. However, considering the relative sizes, I think it would be more accurate to say the door mat is blending into the package rather than the other way around.

Anything small enough to convincingly hide under the door mat would be better off going through a mail slot or going into a mail box. If you want to stop porch pirates from stealing something that big, trying to hid it isn't a good option.