We are into the second week for the Butterfly Challenge already
and here is some more inspiration for you showing that you don't have to have a fancy window die or even a window stamp to take part.
First up is a card using an oblong rectangle die cut (this one is by Crafts-Too PCD98) but you could cut your own aperture. The image is by Hunkdory from their Little Book of Flowers and shows a vase of Tulips on a window sill. Perfect! I merely used very thin d.s tape to make the window panes pattern (leaving the tape intact and not removing the covering). I placed a sheet of acetate behind the framework and then attached the picture behind that. The frame and image were then adhered to the base card front which I had cut from cardstock to fit. Rose coloured butterflies were die cut using SU's Beautiful Wings Embosslits and the pearls came from my stash.
Taken here at an angle to catch the light in order to highlight the acetate.
Second card just sort of evolved really from a selection of diecuts that I had pulled out as possibles to use.
I started off with the insert die cut frame from the card above and selected a smaller die cut to make a further frame. This time I used offcuts to make up the crossbars for the window which were attached from behind before adding the acetate. Then I went to town using the following die cuts to create the flowers, window boxes ,border and a punch for the butterflies.
Poppy Stamps 'Small flower box style 823'
C.C. Designs 'Flower border'
Clearly Besotted 'Fresh grass die'
Craft Stash 'Meadow border DIOB0079'
Tonic Studios 'Small butterfly punch'
I cut both of the flower strips in green first and then again in various flower colours and fussy cut the flowers out and adhered to the green bases. The small strip of flowers was cut up into sections and added built up behind the flower boxes for a 3d effect. The grass was die cut twice and then each one cut in half and added behind the flowers. Boxes were then attached to the window frame. The larger strip of flowers was attached below the window frame to create a flower bed. You can see a little better in the photo below where I have added check curtains (from a snippet of design paper) to the windows and made folds in them to look more realistic. Window frame was adhered to the front of the card and raised up on on 3d pads so as to not to crease the curtains. Well I wasn't about to get the iron out and start ironing them !!!! Butterflies were punched from a snippet of rose cards stock and liquid pearls 'white opal' added to their bodies.

Entering this card into the following challenges: