[{"_id":{"$oid":"5ffb0c14dd482daa039ee906"},"imageUrls":["image url1","image url2"],"time":342432432432},{"_id":{"$oid":"5ffb0c14dd482daa039ee907"},"imageUrls":["image url3","image url4"],"time":342432432433}]

db.collection.aggregate([{$sort:{time:-1}},{$project:{imageUrls:1}},{$unwind:"$imageUrls"},{$facet:{result:[{$skip:0},{$limit:2},{$group:{_id:null,imageUrls:{$push:"$imageUrls"}}}],count:[{$count:"count"}]}}])