This pattern can either be a cross shape or a box divided by a fancy plus mark (see caption of weaving diagram).
This one was a bit of work.
There are several versions of this pattern. The one I chose to focus on has an extra row of plain weave on R2. Other versions eliminate that row and expand the heart to the very edges of the square. It’s easy enough to create a Solid Heart by just filling the shape with U3s. Double Outline hearts can sometimes be a bit tricky. If I feel so inclined (or if someone requests it) I can work on Double Outlines for the other versions.