Delay in showing Twitter Card image

[Juliayaz]

Hi,

I am having an issue with images not being shown at time of the post. There seems to be a delay and I would like to know if I can correct this.

For example, at the time of the post for the URL http://ghosttownmagazine.com/?edition_id=86e92010-1437-11e5-8475-002590a5ba2d, there was no image.

See

And a few hours later, the image is showing correctly. See image here; https://twitter.com/GhostTownsMag/status/610822124115226624

So why the delay? What can I do to correct?

Thanks much, J