I have the same problem with elastic skin of the big pic occupying all the space available in the email panel, I tried to change the css files and nothing good happened, finally I simply changed the svg image size to 50x50px and that did the trick, for the moment at least
Uploading an image for the contact will show the image just as big as originally imported.
Many months passed by since people begun to notice these roundcube errors, seems that it is still the same, 1.4, big image, and probably other errors.
One that s not minor that I found out on my server is that using elastic skin when I reply or wrtie a new email, despite having settled the configuration to always use HTML, the editor's tools to format the text do not appear nowhere, also the emoticons do not appear (I enable the emoticons plugin).
I have no idea about how to solve this one...