Did a search at several shoe sites, got a few close ones, but nothing quite as bare as the one pictured. The ones I found all either had a 2nd strap at mid-foot or at the ankle.
Here is one that is NOT as pretty as the one you have pictured, and again, has a 2nd strap at midfoot.
Some shoes I found that were just a single strap at the front always had a thicker strip of material for added support. It does seem the ones you have pictured would be very challenging to wear in any practical sense.