Image not showing for Summary Large Card

[Berry]

Hi,
I use the card validator to validate my url but the preview or the actual tweet is not showing my image. There is no error at all. Can someone help ? My url is : https://www.youth.sg/Our-Voice/Opinions/2017/5/The-imperfect-dream-job#.WRl5oph44V8.twitter

My image size is 800 by 534 and is based on the Twitter recommendation:
Images for this Card support an aspect ratio of 2:1 with minimum dimensions of 300x157 or maximum of 4096x4096 pixels. Images must be less than 5MB in size. JPG, PNG, WEBP and GIF formats are supported.

Thank You.

[andypiper]

The image that you’re linking to in the twitter:image tag is 150x150 pixels which is too small for a summary large image card.