the way its coded is not well adjusted for tablet or mobile view from what I saw. doesnt not allow for tablets. The great thing is that your site seems user friendly, but with the layout seems a little chaotic to those who visit your site.
You have a very nice AVERAGE website... but I think that for the amount of magic that your paintings convey, you need a more magical or at least colorful website. Maybe add one of your paintings as the background...
One suggestion- consider a trial period on the site for say a month or so (depending on your regular traffic quote) of removing all the :
Regular price: $750.00save 81%
Time left: 7 Hr 10 Min Time left: 7 Hr 10 Min
While I understand the thinking behind this selling format- so does everyone else lol the potential clients know that the "today price" will be available to them at any point.
Discounts Coupons Special offers etc seem to have the affect of cheapening the art and leave clients wondering why you have steep discounts. (is it poor quality? can he not sell anything? why is he so desperate for a sale?) than they hesitate or dismiss a purchase.
Possibly try the site with just set prices comparable to your sale price, notice your traffic (install view counter if needed) while tracking your sales. Offer discounts as SHIPPING to still provide a purchase incentive with out lowering the preserved value of the art it self.
You can always return to the sale format with minimal damage.
Just a suggestion from experience. BEST OF LUCK IN ALL YOU DO!