"-로 만든" => made from; made out of.
-(으)로 has many meanings, one of which is to indicate "the means by which something is made or done".
"여름느낌 물씬 나는 오늘 클래스" => Today's flair [classiness, chicness] with an oozing sense of summer.
* 여름느낌: feeling, sense of summer.
* 물씬: adverb describing an appearance that suggests being steeped in or oozing with something.
* 나는: adjective form of 나다. gives/comes off, evokes (a certain thought/sense), takes place (=일어나다), etc.
* 오늘 클래스: today's flair; today's fashion theme, chicness, etc.
클래스 seems to be used a lot to refer to a classiness, flair, or high sense running through fashion or artistic works.
This is a fairly recent usage, so your phrase may be using it in a different sense too - only the context can tell for sure.
Combined, it may be "Today's flair made from ... and oozing with a sense of summer.