But there are a number of issues with this - storage is one of them, but also copyright, liability, privacy etc. What if someone uploads a photo of his naked girlfriend or the ISIS flag? I don't want to be responsible.
For possible inappropriate photos, I think there should be control on two levels: 1) Require 10 published reviews to allow multiple photo upload. By then there should be only well known and responsible members on our community. At this moment there are 64 of them. 2) Below each photo carousel should be a link "Report inappropriate content" for community users to flag immediately if a misconduct happens.
About storage concerns, it could be max 3 photos / review and maximum size limited to e.g. 800 x 600 pixels. Then photos are 100–250 kB depending on the content and the level of compression. Someone with better mathematics skills can calculate what the sum would be :)
I would prefer photo carousel on reviews, not on each WHS site page. I think the common use case is that a user want to show on photos something she/he writes on review.
POC approach is reasonable.