It may not be apparent the viewer has not seen all the blocks of the poster

[anton-trunov]

It may not be apparent that there is some more blocks than fits the screen. E.g. with my default settings I need to scroll horizontally to see all the blocks of the template poster. So I see the following on my screen and there is no indication I should scroll to the right to see the rest of the poster, which can be a bit confusing.

[cpitclaudel]

I've been pondering how to solve this. The problem is that each poster defines a "natural width" in terms of a number of columns (here, 4). If the poster narrows too much it will be clear that there's stuff left; but when there are more than that number of columns they are not immediately visible. I wonder if there's a CSS trick that we could use here. Otherwise a small amount of JavaScript should be enough.