Remember that we are moving toward consumer friendly content. So putting in a ton of keywords that are just for crawling purposes will not win on Google, you must provide value. But, do not misunderstand keywords are valuable.
PAGE TITLE: Should be geared toward high value keywords; List of Ice Cream Flavors, Best Ice Cream Flavors.
IMAGE NAME: Long Tail Keywords; Good Old Vanilla Ice Cream, Best Ice Cream Flavors in Summer. Ice Cream Flavors With A Little Twist.
IMAGE ALT:Should be specific to the picture. Remember people most people only look at the first page in a search result but when looking for images they tend to search through 2-4 pages (and can do it in seconds)!
I use the On-Page Optimization Tool in Moz to determine my page score for a specific keyword.
On-Page Ranking Factors
All the best,