This player only supports pictures in JPEG format. Make sure that the file extension is .jpg, .JPG, .jpeg or .JPEG.

Specifications of JPEG files supported:

Upper limit: 2,560 x 1,900 dots (sub sampling is 4:4:4) OR 5,120 x 3,840 dots (sub sampling is up to 4:2:2)
Lower limit: 32 x 32 dots 
Maximum file size of a picture: 12MB