In terms of web page it is good; reads fast, HTML ok, good graphics, etc.
In terms of art presentation, it needs art information. That is, for each art picture, insert some information, at least name, art type, size, medium used, date done, price if applicable.
If there are any design specific forums that have a review my work feature you could try posting there, otherwise, as long as you have good content then Google etc should rank you well. This is why it's important to have textual details about the image, as otherwise Google has no idea what it is looking at.