Eh, not likely, they will key on scent and heat signal for the most part, sight is only for the actual strike.
I take it that you feed live? Switch to f/t (frozen and thawed) or p/k (pre-killed) as soon as possible imho. Less stress for rodent and snake and a dead rat can't hurt your snake.
Aspen is ok to feed on, has some risk but I know a lot of breeders who do it. I personally would suggest to never feed in the enclosure unless you use a rack system and own multiple snakes. With only a few, feeding in a separate bin is so easy and has so many benefits.
Cheers!
Fatal