http://www.millimillu .com (not a client of mine – I've broken the hyperlinks) is at time of writing (30.7.16) ranking around 18th on google.co.uk for "luxury handbags" (for which exact phrase alone there are around 720 searches monthly on google.co.uk according to their Keyword Planner). The page ranking is a blog tag page: www.millimillu .com/the-diary/tag/luxury-handbags/ (which Google is most likely to consider a relatively low quality page as it's just fragments of other blog posts). It is likely will not convert as a landing page as well as a product or category page would as it is a blog list page.
The main reason this page (of all the others from the site) is ranking is that it's considered to be the most relevant page from the site for this phrase – there are only internal links to this page (i.e. there's no external links to this page according to majestic.com) and it's only got a few words on it. The site may be considered to have a high-quality backlink profile as the fact is this page is ranking when the site is not optimised for this phrase at all in my opinion. It's worth noting that they do not appear to be targeting any other key phrase other than "(Chic) Handbags" - they aren't in the top 100 on google.co.uk for "Handbags" nor "Chic Handbags" according to a check in my browser.
In short, based on a 'blink analysis' it would appear that little or no on-page optimisation for search engines has been done (at least for the phrase "luxury handbags" or apparently even for "handbags" - see http://www.millimillu .com/all-bags)! The millimillu .com site is ranking 'by accident' for this phrase on account of the backlinks to the site.
To boost their organic ranking they need to:
1. implement keyword research-led optimisation of:
2. noindexation of blog tag pages e.g. www.millimillu .com/the-diary/tag/luxury-handbags/
3. inbound link building (based on competitor analyses) as this is a competitive area with some big names ranking in the top 10.
Update Jan 2017: I contacted them to no avail on this issue and the situation remains the same - they are now bidding on Adwords for the phrase "luxury handbags"!!?