ᐅ Several Ikea Ribba picture frames combined to create one large picture display

Hello,

I recently saw this decoration at an IKEA store.

How were the individual Ribba picture frames assembled?
I don’t think hot glue is the best option for this.

Regards,
Spiku

Could you see behind it? I would initially assume the frames are mounted on a support panel.

Unfortunately not, because the collage was placed directly against the wall.

I would agree with the IKEA expert. It looks like the shadows suggest there is a gap between the wall and that the frames are mounted on a separate panel.