Plugin Author
ntm
(@ntm)
The feed http://www.wdwhappyplace.com/feed/ contains the RSS and iTunes:images with sharp (and not rounded) corners. (I guess that these are the new ones.?)
The iTunes server visits your blog usually once every day and updates all information (see http://www.apple.com/itunes/podcasts/specs.html#itunesclient). It is important that you use a different file name when you change your RSS or iTunes image (see http://www.apple.com/itunes/podcasts/specs.html#image).
You RSS feed looks fine and is valid. iTunes should have no problem updating the image. Maybe it takes a little bit longer these days (see http://ww.wp.xz.cn/support/topic/plugin-podpress-podcast-image-not-showing-up-in-itunes).
But it seems that your iTunes image has been upload in the last 24h. Maybe wait one more day.