It is a double clamp system based on compliant mechanism, one clamp to tie the string an one other to tie the photo
Printed on my PRUSA MNI+ with pearl white PLA, 0.4mm nozzle 0.1 mm layer
No support
Easy to assemble, no glue
For the spring design, I made some FEM simulation on FreeCAD to find the right proportions
The author marked this model as their own original creation.