PageCloud makes it very easy to bring elements or designs from Photoshop into your PageCloud site.
Currently, you are able to copy layers after they've been flattened. Please keep in mind that Layer Groups would need to be merged first. Once this is done, you can select all (CMD/CTRL + A) to select the layer and then hit copy (CMD/CTRL + C) to bring it into your clipboard. Navigate to your PageCloud page and hit paste (CMD/CTRL + V) to paste that layer onto your page.
Another option to help make the image more manageable is to save it as a PNG or JPG and then drag that from your computer into PageCloud.
As this method makes use of your computer's clipboard, it's important to note that this will not support transparencies. For that, you will want to save the layer/image as a PNG and then drag it from your desktop into your PageCloud site.