I'm thinking the lace covers the front and is adhered to the back of the heart and the heart is well adhered to the front of the pocket.
OK the simplest way is that the square and the heart are separate and the lace acts as the fold to hold them together. There is no indication on what the lace looks like on the back so it could just crisscross to the back edges.
Another way is work with folds which starts getting more complicated (have to be very careful with adhesive placement on pocket cards) and may need an electronic cutter.
Looking at it again...
It looks like a variation of her "Modern 4 fold invitation" - might try the "Square Petal Card" template with a few adjustments to round them more for the "heart effect" -
Templates ? Paperandmore.com and just cut two of the petals that are beside each other. The lace would cover where the folds join.
Hope that gives you some ideas on how to approach this.
FWIW I would do a test run before I xyron the lace. Getting all the adhesive out of all those small holes would be a nightmare. Could just be some carefully placed matt glue under the most opaque parts of the lace.
Need help making this card holder!
