Nice pictures of beautiful women will always get a large amount of views/likes (and NSFW warnings that imply nudity don't hurt either). There's not much confusion as to why photo 1 is more popular: sex sells. She's got some ridiculous side boob going, and her breasts are much more emphasized with the posing of her body that way. I bet if she were topless you'd have 10x as many views, and if she were full nude 10x that.
WHO views/likes them is a whole 'nother matter. People who are concerned with the breast size of a model: usually looking for some sort of sexual gratification from looking at the image. Also, as a photographer (as someone else already pointed out): what does photographers liking/following you do for you? It doesn't get you work, and it doesn't get you more models to shoot with. I'm willing to bet the majority of views were other photographers, or just random dudes who saw an attractive woman. Not really beneficial to a photographer to be honest. I'm unfamiliar with 500px, is there a way to track views? Are there comments or likes, and if so is there a way to view who did/said what?
The goal should be to shoot photos that models/women (or men if that's your specialty) enjoy and want for themselves. Once you do that, women will be begging to work with you for what you can provide them. Even better, shoot photos that commercial clients want/demand (=$$$).
Now, onto your question: Does breast size matter for the shoot you want to do (or in general)? Yes. If you cater to GWC's and guys (or gals) wanting to oogle some large breasts...then yes, they most certainly matter. In general, if you're just wanting to take good photos...then no. C-D-EEE, it's all the same, unless your focus is on the breasts and they're the subject of your photos. I used to keep track when I was still using tumblr, and from time to time look through IG posts as well: When I post a random photo of a girl wearing t-shirt and jeans = a couple likes and comments or reblogged a couple dozen times. When I post a model in swim/lingerie = 5-10x more "action". When I post a nude shoot = "100-1000x" more views/reblogs/etc. When I post a fully styled, thought out concept with hair/makeup = almost as many as the nude, but not quite usually.
What I noticed with all that though is that stylists and clients responded to the tee/jeans, and styled shoots, models/makeup/hair/women -in-general responded to those, and the lingerie/swim, and maybe 80% percent random dudes and photographers and 20% women responded to the nudity. Take from that what you will.
So again, does breast size matter? I guess it depends on who you're trying to attract.