That's looking quite good to me. All stiltons at 4-5 weeks are scary-looking things, but you have a good mix of blue and white moulds and nothing unhealthy-looking. I can see you've pierced it, so those blue moulds should be getting the air they need inside the cheese to work their magic.
Two things jump out at me. Your stilton is quite spread out at what is the top in the photo, which suggests to me that perhaps you've not been turning it as much as it would like or that it was still a bit too wet when it came out of the mould. The fact that the blues are only on the top suggest that you have been keeping it at slightly too low humidity. Have you been turning it daily? Also, what does it smell like? Does it smell like stilton, or are you getting an ammonia air from it?
While keeping a stilton, I'd recommend that you turn it daily and also to take it out for half an hour or so each day to let it breathe so the ammonia from the bacteria doesn't build up.
Edited to add: I can see that the sides of your stilton are going a bit brown as the moulds die down. Mine do that as well at around the 4-5 week stage. You may like to let it dry out a bit so it's a bit less slimy, or consider eating it now or vacuum-sealing it for later at this stage.