Validation of podcast

If Soundcloud is messsing up your image I'm afraid I can't help with that: see if they have a support contact. You could also have a close look at their settings in case there is something which affects the image. Other people have had Soundcloud feeds accepted so there presumably must be a way to get the image right.

Also it appears they have a forum, so that would be a good place to ask:

https://community.soundcloud.com/\

Your image URL is http://i1.sndcdn.com/avatars-000753231124-2st44j-original.jpg

This is 426 x 426 px - well below the minimum requirement of 1400 x 1400 px. Are you sure you are creating a properly sized image before submitting it to Soundcloud? If they are resizing it (which would seem to be an odd thing to do) I can't advise on what they are up to and can only suggest you contact their Help. But do check your initial image parameters carefully.