For ALL the images on the site are here:
assets/images/

Services (images):
assets/images/services

Bathroom (image):
assets/images/bathroom.png
assets/lib/front_ajax.php - Line 904

Bed (image):
assets/images/bed.png
assets/lib/front_ajax.php - Line 897

Admin Login (image):
assets/images/login-bg.png

assets/images/login-bg-1.png

Add-ons (images):
/assets/images/addons-images/