I did a inspection in your images now, and all are being rendered with the same size 634x346, that’s correct. But even if we resize the browser, we still have alignment issues because the number of words on each text column are different. This will works only if you have the exactly same number of words in the texts at each column.
I propose for you a different approach. Edit your images by removing the gradient and shadow effect:
Make the images with a solid (no gradient) color. This way we can add custom CSS with the respective image color to fill the space that appears below the images. For example:
No that in the above image, the widget background is with a solid color that fits with the left side of the image. If we have all the image with the same color, then the problem will be resolved (removing gradient and shadow from image).
This way you can define custom class name for each column widget and then apply the respective image color in the background.
We hope this helps!
Please try that and let us know if you need further assistance.