I think it's slightly ambiguous wording "burst blood vessels", where "burst" is an adjective, not a verb. So burst blood vessels are something it covers up, along with age spots and other blemishes.
It's technically a past participle I think (similar to how "wrapped" functions in "wrapped sandwich"). The ambiguity in this case stems from the fact that the present tense verb is also "burst" and the sentence structure makes it easy to be misinterpreted.
