  The Large High-Altitude Air Shower Observatory (LHAASO) recently published
measurements of diffuse Galactic gamma-ray emission (DGE) in the 10-1000 TeV
energy range. The measured DGE flux is significantly higher than the
expectation from hadronic interactions between cosmic rays (CRs) and the
interstellar medium. This excess has been proposed to originate from unknown
extended sources produced by electron radiation, such as pulsar wind nebulae or
pulsar halos (PWNe/halos). In this study, we propose a new perspective to
explain the DGE excess observed by LHAASO. The masking regions used in the
LHAASO DGE measurement may not fully encompass the extended signals of
PWNe/halos. By employing a two-zone diffusion model for electrons around
pulsars, we find that the DGE excess in most regions of the Galactic plane can
be well explained by the signal leakage model under certain parameters. Our
results indicate that the signal leakage from known sources and contributions
from unresolved sources should be considered complementary in explaining the
DGE excess.
