The first and second acts of The Portrait had me fairly hooked. It's a slow-burn psychological drama/thriller centered around a supposedly haunted painting. Though the writing goes through the motions, at least director Simon Ross worked out the atmospherics quite nicely. The protagonist (played by Natalia Cordova-Buckley) isn't given enough layers for us to care, but the actress (especially her grief-stricken face) gives more to the character than the writing. The film mostly shuffles between supernatural horror and psychological thriller but doesn't firmly place its foot on either. As a result, we get moderately enjoyable scares, an interesting backstory regarding the person in the portrait, and how it may or may not be connected to present events.
However, the last act was completely lost on me. It works from a visual standpoint, but when perceived from the writing and performative fronts, it's a letdown. For this to have worked from a psychological angle, I think we needed more scenes of the couple in their past (in order to connect with their present better), as well as more light shed on the 1937 backstory. Here, it's all told in a rushed fashion, with a conclusion that doesn't serve this story right. There's also a closing shot (twist?) that only waters the entire viewing experience down further.. almost as if the story we just watched never really mattered in the first place.