The ornamental design for a mobile phonecase, as shown and described.
FIG. 1 is a front view of a mobile phone case showing our new design;
FIG. 2 is a rear view thereof;
FIG. 3 is a left side view thereof;
FIG. 4 is a right side view thereof;
FIG. 5 is a top plan view thereof;
FIG. 6 is a bottom plan view thereof; and,
FIG. 7 is a rear perspective view thereof showing the back cover in an open position and an environmental card enclosed therein.
The broken lines throughout the drawing disclosure depict an environmental card and portions of the mobile phone case that form no part of the claimed design. The broken lines and unshaded regions bounded by broken lines form no part of the claimed design.