Adhesives for Wall Tiles?

If you want something other than tile mortor, you could use LePage PL Premius construction adhesive. Or, any similar product.

would "crazy glue" work?

You might try liquid nails, or epoxy.

I would not use crazy glue for that application.

nope

What was the mortar application all about?

This would be thinset mortar that is used specifically for this type of application. You can get it at most any hardware or Home Depot

Good idea!

silicon adhesive is strong as hell, in my trade we use it to glue granite slabs to interior walls

Do not use liquid nails to adhere wall tiles. It continues to shrink over time, and the tile glaze will "craze".

Do not use silicone either. It is too flexible. Sure you can use it for rigid marble, but wall tiles are too fragile, as are most ceramic floor tiles.

Any tile shop can sell you a small tub of premixed multi-purpose tile adhesive, and a plastic notched trowel.