The Cambridge Grammar of the English Language by Huddleston and Pullum (2002) says on p.1152 about as if/though:
The as if/though construction is one of those that allow irrealis were or a modal preterite. Where the matrix clause has present tense, we have the expected contrast in the content clause between were or modal preterite and present tense:
 He moves about on camera, angular, emaciated, graceful, as if his body were/is weightless.
The version with irrealis were is motivated by the fact that his body is not actually weightless, i.e. by the counterfactuality of the content clause. The version with is, by contrast, presents his body’s being weightless as an open possibility, thereby suggesting that he gives the appearance of being weightless. Compare also She acts as if she hated me and She acts as if she hates me [...]. The latter conveys that the way she acts suggests that she does hate me or may well do so, whereas the modal preterite hated presents her hating me as a more remote possibility (though it is certainly not presented as counterfactual).
The interpretation of your sentence is parallel to the ones provided for the examples in the excerpt above.