Anyone enjoy scrutinizing pictures to explain away potential paranormal photobombs?

My row house was built in 1908, and I've long suspected that a ghost resides here. I've never seen anything, but there's an area in the front part of my second floor hallway and parts of the 3rd floor that give me mild heebee jeebees (and the baker's alley in the basement just flat out freaks me the fuck out, and I refuse to enter it unless someone is with me). When I hit these spots at times, my heart rate will just explode for no reason, I'll tense up, and I'll get an extremely strong, extremely distinct impression of a woman in her 30s wearing a shirtwaist and a long dark skirt. She's not scary, she gives me the impression of being a guardian/someone who loves this house as much as I do, but my body just goes into hardcore flight mode even though my brain is totally okay with what I'm picking up/noticing.

Tonight, I returned home from an award ceremony and immediately rearranged a bookcase shelf in my living room to display a lovely bouquet of silk flowers a friend gifted me in honor of my award. I snapped a pic to send her, and I was amused by a swoopy thing in the corner of the pic. It can't be the result of a light source as the sun was just a few minutes from fully setting, I'm penned in by a bunch of other row homes, and my windows are all north-south with drawn blinds. I had 2 light sources on at the time, both of which were well behind me and on opposite ends of the first floor (that is, nowhere near me or the bookcase. Also, the brighter of the two sources was a chandelier to my left mounted to a 9 foot ceiling with cups that direct the light up towards the ceiling instead of down/out). I snapped several pics, and none of them have this corner swoop thing except this one. When I saw it, my first thought was, "Why, hello, Grey Lady! Have you gotten bored of the hallways upstairs?"

So. . .does anyone have any theories regarding that white streak in the corner? Think my possible ghostie came down to inspect the flowers, or am I just having too much fun with a random irregularity in a cruddy cell phone pic taken at dusk?

ETA: since the picture posted at a massive size here, I've been able to scrutinize it further and am amused to note that you can see the brighter circle in the center of the pic caused by the flash and how the edges get darker beyond the flash's perimeter, but the white streaky thing is consistent in its color and opacity despite passing through two of the darkest spots at the bottom and left frame and a slightly lighter flash-spot in the middle of its border. I'm super entertained by this.