I've been dying to make one of these for a few weeks now - you wouldn't believe how many I have pinned on Pinterest! I ended up making three of them because I found three different sizes on various blogs and wanted to see which I liked best. I really don't think it matters because I like them all. The first one on the left is from the Splitcoaststampers tutorials section and it's 5 1/2 x 6 when closed. The other two are basically the same except that the middle one is a little taller so that it is 6 x 4 1/4 when closed and the smallest one is 5 1/2 x 4 1/4 when closed.
The basic box is very easy to put together and then the "filling" does take a little time, but well worth it. I cut all the hearts out with my Silhouette, as well as the hearts flourishes. The stamp is from my stash done in Firecracker Red embossing powder (SNS). The white background heart is done with a white microfine glitter on sticky paper and the red heart on the right with Gypsy Red microfine glitter (also SNS).
Here is another view:
The second "box/card" has a birdcage to match the DP that was an SVG file from Bird's Cards.
And the third "card/box" has two digi images in it that were colored with Copics. The heart balloons are also from Bird's Cards and the little dog is from Little Scraps of Heaven (digis I've had for a while).